Pyrazolo-pyrrolidin-4-one derivatives as bet inhibitors and their use in the treatment of disease

ABSTRACT

The present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof; (I) a method for manufacturing the compounds of the invention, and its therapeutic uses. The present invention further provides a combination of pharmacologically active agents and a pharmaceutical composition.

FIELD OF THE INVENTION

The invention provides pyrazolo-pyrrolidin-4-one derivatives and theiruse as BET inhibitors, for the treatment of conditions or diseases suchas cancer.

BACKGROUND OF THE INVENTION

BET proteins are proteins encoded by either of the genes BRD2, BRD3,BRD4, or BRDT. Each of these proteins bears two N-terminal bromodomains.Bromodomains comprise of a conserved ˜110 amino acid segment found in atleast 42 diverse proteins that specifically interact with acetylatedlysines that occur for example on histone tails (Filippakopoulos andKnapp, FEBS Letters, 586 (2012), 2692-2704). Histones are a constituentpart of chromatin and their covalent modifications including lysineacetylation regulate gene transcription. Bromodomains are thus believedto regulate transcription by recruiting proteins to genes that aremarked with specific patterns of lysine acetylation.

Several published reports have linked the BET protein family to diseasesincluding cancer, metabolic disease and inflammation. Oncogenic fusionsof BRD4 or BRD3 and the Nuclear protein in Testis (NUT) gene caused bychromosomal translocations are underlying an aggressive cancer named NUTmidline carcinoma (French et al., J Clin Oncol, 22 (2004), 4135-9;French et al., J Clin Pathol, 63 (2008), 492-6). The BRD3/4 bromodomainsare preserved in these fusion proteins, and their inhibition either byknockdown or with the selective BET bromodomain inhibitor JQ1 leads todeath and/or differentiation of these cancer cells both in vitro and inanimal tumour models (Filippakopoulos et al., Nature, 468 (2010),1067-73). JQ1 and several other selective BET inhibitors have been shownto bind to BET bromodomains and thereby prevent acetyl-lysine binding,which prevents BET proteins from interacting with chromatin and therebyregulating transcription. BRD4 was also identified from an RNAi screenas a target in acute myeloid leukemia (AML) (Zuber et al., Nature, 478(2011), 524-8). This finding was validated in vitro and in vivo usingthe BET inhibitor JQ1 and another selective BET inhibitor named I-BET151that is chemically unrelated to JQ1 (Dawson et al., Nature, 478 (2011),529-33). These and other studies showed that BET inhibitors have broadanti-cancer activity in acute leukemias, multiple myeloma and otherhematological malignancies. In several cancer models an acutedownregulation of the oncogenic transcription factor Myc upon BETinhibition has been observed (Delmore et al., Cell, 146 (2011), 904-17;Mertz et al., Proc Natl Acad Sci USA, 108 (2011), 16669-74). More recentstudies suggest that the therapeutic potential of BET inhibitors extendsto other cancer indications, for example lung and brain cancer.

Another BET inhibitor named I-BET762 that is closely related to JQ1 inchemical structure and the manner in which it binds to BET bromodomains,was reported to modulate expression of key inflammatory genes andthereby protect against endotoxic shock and bacteria-induced sepsis inmouse models (Nicodeme et al., Nature, 468 (2010), 1119-23). This bodyof data has been used to support the clinical evaluation of the BETinhibitor RVX-208 in clinical trials in patients suffering fromatherosclerosis, coronary artery disease, dyslipidemia, diabetes, andother cardiovascular diseases (McNeill, Curr Opin Investig Drugs, 3(2010), 357-64 and www.clinicaltrials.gov), Both RVX-208 and I-BET762have been shown to upregulate Apolipoprotein A-I, which is criticallyinvolved in reducing the tissue levels of cholesterol. Finally, BETproteins have been linked to propagation and transcription regulation ofseveral viruses, and therefore it is believed that BET inhibitors couldhave anti-viral activity (Weidner-Glunde, Frontiers in Bioscience 15(2010), 537-549).

In summary, inhibitors of BET bromodomains have therapeutic potential inseveral human diseases.

SUMMARY OF THE INVENTION

There remains a need for new treatments and therapies for the treatmentof cancer. The invention provides compounds as BET inhibitors,pharmaceutically acceptable salts thereof, pharmaceutical compositionsthereof and combinations thereof. The invention further provides methodsof treating, preventing or ameliorating cancer, comprising administeringto a subject in need thereof an effective amount of a BET inhibitor.

Various embodiments of the invention are described herein. Particularlyinteresting compounds of the invention have good potency in thebiological assays described herein. In another aspect they should have afavourable safety profile. In another aspect, they should possessfavourable pharmacokinetic properties.

According to a first aspect of the invention, Embodiment 1, there isprovided a compound of formula (I) or a salt thereof,

wherein

A is selected from

B is

C is

R¹ is methyl, optionally substituted with one or two fluoro;

R² is selected from chloro and fluoro;

R³ is selected from (C₁-C₄)alkyl and cyclopropyl; and R⁴ is selectedfrom (C₁-C₄)alkyl, optionally substituted by —OH or —O—(C₁-C₄)alkyl;halo(C₁-C₄)alkyl substituted by —OH; or

or

R³ is

and R⁴ is selected from H; (C₁-C₄)alkyl optionally substituted by —OH or—O—(C₁-C₄)alkyl; and cyclopropyl; R⁵ is H;

R⁶ is selected from methyl, methoxy, —NH₂ and —NH—C(O)—(C₁-C₄)alkyl

R⁷ is methoxy; and * indicates the point of attachment to the remainderof the molecule.

In another embodiment, the invention provides a pharmaceuticalcomposition comprising a therapeutically effective amount of a compoundaccording to the definition of formula (I), or a salt thereof, orsubformulae thereof and one or more pharmaceutically acceptablecarriers.

In another embodiment, the invention provides a combination, inparticular a pharmaceutical combination, comprising a therapeuticallyeffective amount of the compound according to the definition of formula(I), or a salt thereof, or subformulae thereof and one or moretherapeutically active agents.

DETAILED DESCRIPTION

Described below are a number of embodiments (E) of the first aspect ofthe invention, where for convenience Embodiment 1 is identical thereto.

Unless specified otherwise, the term “compounds of the presentinvention” refers to compounds of fomula (I) and subformulae thereof,and salts thereof, as well as all stereoisomers (includingdiastereoisomers and enantiomers), rotamers, tautomers and isotopicallylabeled compounds (including deuterium substitutions), as well asinherently formed moieties.

Unless specified otherwise, the term “compounds of the presentinvention” refers to compounds of fomula (I) and subformulae thereof,and salts thereof, as well as all stereoisomers (includingdiastereoisomers and enantiomers), rotamers, tautomers and isotopicallylabeled compounds (including deuterium substitutions), as well asinherently formed moieties.

As used herein, the term “C₁₋₄alkyl” refers to a fully saturatedbranched or unbranched hydrocarbon moiety having 1 to 4 carbon atoms.Representative examples of C₁₋₄alkyl include methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, iso-butyl and tert-butyl.

Various embodiments of the invention are described herein. It will berecognized that features specified in each embodiment may be combinedwith other specified features to provide further embodiments of thepresent invention.

The invention therefore provides a compound of the formula (I) asdescribed hereinabove as Embodiment 1.

Embodiment 1.1. A compound of formula (I) or a salt thereof,

wherein

A is selected from

B is

C is

R¹ is methyl, optionally substituted with one or two fluoro;

R² is selected from chloro and fluoro;

R³ is selected from (C₁-C₄)alkyl and cyclopropyl;

R⁴ is (C₁-C₄)alkyl, optionally substituted by —OH or —O—(C₁-C₄)alkyl;

R⁵ is H;

R⁶ is selected from methyl and methoxy;

and * indicates the point of attachment to the remainder of themolecule.

Embodiment 2. A compound of formula (I), or a salt thereof, according toEmbodiment 1, which is of the formula (Ia):

Embodiment 3. A compound of formula (I), or a salt thereof, according toEmbodiment 1 or 2, wherein the compound is of the formula (II) or (IIa):

Embodiment 4. A compound of formula (I), or a salt thereof, according toany preceding Embodiment, wherein R¹ is selected from methyl anddifluoromethyl.

Embodiment 5. A A compound of formula (I), or a salt thereof, accordingto any preceding Embodiment, wherein A is selected from

Embodiment 6. A compound of formula (I), or a salt thereof, according toany preceding Embodiment, wherein R² is chloro.

Embodiment 7. A compound of formula (I), or a salt thereof, according toany preceding Embodiment, wherein R³ is selected from methyl, ethyl andcyclopropyl.

Embodiment 8. A compound of formula (I), or a salt thereof, according toany preceding Embodiment, wherein R³ is cyclopropyl.

Embodiment 9. A compound of formula (I), or a salt thereof, according toany preceding Embodiment, wherein R⁴ is methyl or —CH₂CH₂OCH₃.

Embodiment 10. A compound of formula (I), or a salt thereof, accordingto Embodiment 1, 2, 3, 4 or 5, wherein R³ is

and

R⁴ is H.

Embodiment 11. A compound of formula (I) or a salt thereof, according toany one of Embodiments 1, 1.1 or 3 to 9, wherein the compound is presentas the racemate of the 2 enantiomeric forms (la) and (Ib) disclosedherein.

Embodiment 12. A compound of formula (I), or a salt thereof, accordingto Embodiment 1, which is selected from:

Example 1:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 2:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 3:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 4:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

6Example 5:-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 6:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

Example 7:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 8:6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 9:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 10:6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxy-pyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 11:(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 12:6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxy-pyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 13:(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 14:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 15:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 16:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 17:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 18:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 19:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 20:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 21:6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 22:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 23:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 24:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 25:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 26:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 27: tert-butyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate;

Example 28:5-(8-amino-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;and

Example 29: ethyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5-(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate

Embodiment 13. A compound of formula (I), or a thereof, according toEmbodiment 1, which is selected from:

Example 2:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 3:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 4:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 7:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 11:(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;

Example 24:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;and

Example 28:5-(8-amino-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one.

The present disclosure includes compounds of stereochemistry is as shownin formula (Ib):

Depending on the choice of the starting materials and procedures, thecompounds can be present in the form of one of the possible isomers oras mixtures thereof, for example as pure optical isomers, or as isomermixtures, such as racemates and diastereoisomer mixtures, depending onthe number of asymmetric carbon atoms. The present invention is meant toinclude all such possible isomers, including racemic mixtures,diasteriomeric mixtures and optically pure forms. Optically active (R)-and (S)-isomers may be prepared using chiral synthons or chiralreagents, or resolved using conventional techniques. If the compoundcontains a double bond, the substituent may be E or Z configuration. Ifthe compound contains a disubstituted cycloalkyl, the cycloalkylsubstituent may have a cis- or trans-configuration. All tautomeric formsare also intended to be included.

As used herein, the terms “salt” or “salts” refers to an acid additionor base addition salt of a compound of the invention. “Salts” include inparticular “pharmaceutical acceptable salts”. The term “pharmaceuticallyacceptable salts” refers to salts that retain the biologicaleffectiveness and properties of the compounds of this invention and,which typically are not biologically or otherwise undesirable. In manycases, the compounds of the present invention are capable of formingacid and/or base salts by virtue of the presence of amino and/orcarboxyl groups or groups similar thereto.

Pharmaceutically acceptable acid addition salts can be formed withinorganic acids and organic acids.

Inorganic acids from which salts can be derived include, for example,hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and the like.

Organic acids from which salts can be derived include, for example,acetic acid, propionic acid, glycolic acid, oxalic acid, maleic acid,malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid,toluenesulfonic acid, sulfosalicylic acid, and the like.

In another aspect, the present invention provides compounds of formula Iin acetate, ascorbate, adipate, aspartate, benzoate, besylate,bromide/hydrobromide, bicarbonate/carbonate, bisulfate/sulfate,camphorsulfonate, caprate, chloride/hydrochloride, chlortheophyllonate,citrate, ethandisulfonate, fumarate, gluceptate, gluconate, glucuronate,glutamate, glutarate, glycolate, hippurate, hydroiodide/iodide,isethionate, lactate, lactobionate, laurylsulfate, malate, maleate,malonate, mandelate, mesylate, methylsulphate, mucate, naphthoate,napsylate, nicotinate, nitrate, octadecanoate, oleate, oxalate,palmitate, pamoate, phosphate/hydrogen phosphate/dihydrogen phosphate,polygalacturonate, propionate, sebacate, stearate, succinate,sulfosalicylate, sulfate, tartrate, tosylate trifenatate,trifluoroacetate or xinafoate salt form.

Any formula given herein is also intended to represent unlabeled formsas well as isotopically labeled forms of the compounds. Isotopicallylabeled compounds have structures depicted by the formulas given hereinexcept that one or more atoms are replaced by an atom having a selectedatomic mass or mass number. Examples of isotopes that can beincorporated into compounds of the invention include isotopes ofhydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, and chlorine,such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸F ³¹F, ³²P, ³⁵S, ³⁶Cl, ¹²³I, ¹²⁴I,¹²⁵I respectively. The invention includes various isotopically labeledcompounds as defined herein, for example those into which radioactiveisotopes, such as ³H and ¹⁴C, or those into which non-radioactiveisotopes, such as ²H and ¹³C are present. Such isotopically labelledcompounds are useful in metabolic studies (with ¹⁴C), reaction kineticstudies (with, for example ²H or ³H), detection or imaging techniques,such as positron emission tomography (PET) or single-photon emissioncomputed tomography (SPECT) including drug or substrate tissuedistribution assays, or in radioactive treatment of patients. Inparticular, an ¹⁸F or labeled compound may be particularly desirable forPET or SPECT studies. Isotopically-labeled compounds of formula (I) cangenerally be prepared by conventional techniques known to those skilledin the art or by processes analogous to those described in theaccompanying Examples and Preparations using an appropriateisotopically-labeled reagents in place of the non-labeled reagentpreviously employed.

Further, substitution with heavier isotopes, particularly deuterium(i.e., ²H or D) may afford certain therapeutic advantages resulting fromgreater metabolic stability, for example increased in vivo half-life orreduced dosage requirements or an improvement in therapeutic index. Itis understood that deuterium in this context is regarded as asubstituent of a compound of the formula (I). The concentration of sucha heavier isotope, specifically deuterium, may be defined by theisotopic enrichment factor. The term “isotopic enrichment factor” asused herein means the ratio between the isotopic abundance and thenatural abundance of a specified isotope. If a substituent in a compoundof this invention is denoted deuterium, such compound has an isotopicenrichment factor for each designated deuterium atom of at least 3500(52.5% deuterium incorporation at each designated deuterium atom), atleast 4000 (60% deuterium incorporation), at least 4500 (67.5% deuteriumincorporation), at least 5000 (75% deuterium incorporation), at least5500 (82.5% deuterium incorporation), at least 6000 (90% deuteriumincorporation), at least 6333.3 (95% deuterium incorporation), at least6466.7 (97% deuterium incorporation), at least 6600 (99% deuteriumincorporation), or at least 6633.3 (99.5% deuterium incorporation).

Pharmaceutically acceptable solvates in accordance with the inventioninclude those wherein the solvent of crystallization may be isotopicallysubstituted, e.g. D₂O, d₈-acetone, d₈-DMSO.

Compounds of the invention, i.e. compounds of formula (I) that containgroups capable of acting as donors and/or acceptors for hydrogen bondsmay be capable of forming co-crystals with suitable co-crystal formers.These co-crystals may be prepared from compounds of formula (I) by knownco-crystal forming procedures. Such procedures include grinding,heating, co-subliming, co-melting, or contacting in solution compoundsof formula (I) with the co-crystal former under crystallizationconditions and isolating co-crystals thereby formed. Suitable co-crystalformers include those described in WO 2004/078163. Hence the inventionfurther provides co-crystals comprising a compound of formula (I).

As used herein, the term “pharmaceutically acceptable carrier” includesany and all solvents, dispersion media, coatings, surfactants,antioxidants, preservatives (e.g., antibacterial agents, antifungalagents), isotonic agents, absorption delaying agents, salts,preservatives, drug stabilizers, binders, excipients, disintegrationagents, lubricants, sweetening agents, flavoring agents, dyes, and thelike and combinations thereof, as would be known to those skilled in theart (see, for example, Remington's Pharmaceutical Sciences, 18th Ed.Mack Printing Company, 1990, pp. 1289-1329). Except insofar as anyconventional carrier is incompatible with the active ingredient, its usein the therapeutic or pharmaceutical compositions is contemplated.

The term “a therapeutically effective amount” of a compound of thepresent invention refers to an amount of the compound of the presentinvention that will elicit the biological or medical response of asubject, for example, reduction or inhibition of an enzyme or a proteinactivity, or ameliorate symptoms, alleviate conditions, slow or delaydisease progression, or prevent a disease, etc. In one non-limitingembodiment, the term “a therapeutically effective amount” refers to theamount of the compound of the present invention that, when administeredto a subject, is effective to (1) at least partially alleviate, inhibit,prevent and/or ameliorate a condition, or a disorder or a disease (i)mediated by BET proteins, or (ii) associated with BET protein activity,or (iii) characterized by activity (normal or abnormal) of BET proteins;or (2) reduce or inhibit the activity of BET proteins; or (3) reduce orinhibit the expression of BET. In another non-limiting embodiment, theterm “a therapeutically effective amount” refers to the amount of thecompound of the present invention that, when administered to a cell, ora tissue, or a non-cellular biological material, or a medium, iseffective to at least partially reducing or inhibiting the activity ofBET proteins; or at least partially reducing or inhibiting theexpression of BET proteins.

A “BET protein” is a protein encoded by either of the genes BRD2, BRD3,BRD4, or BRDT″. Unless indicated otherwise “BET proteins” or “BETprotein” are used herein in the singular and plural formsinterchangeably, and the use of either is not limiting. Unless indicatedotherwise “BET proteins” includes all, or any combination of, suchencoded proteins.

As used herein, the term “subject” refers to an animal. Typically theanimal is a mammal. A subject also refers to for example, primates(e.g., humans, male or female), cows, sheep, goats, horses, dogs, cats,rabbits, rats, mice, fish, birds and the like. In certain embodiments,the subject is a primate. In yet other embodiments, the subject is ahuman.

As used herein, the term “inhibit”, “inhibition” or “inhibiting” refersto the reduction or suppression of a given condition, symptom, ordisorder, or disease, or a significant decrease in the baseline activityof a biological activity or process.

As used herein, the term “treat”, “treating” or “treatment” of anydisease or disorder refers in one embodiment, to ameliorating thedisease or disorder (i.e., slowing or arresting or reducing thedevelopment of the disease or at least one of the clinical symptomsthereof). In another embodiment “treat”, “treating” or “treatment”refers to alleviating or ameliorating at least one physical parameterincluding those which may not be discernible by the patient. In yetanother embodiment, “treat”, “treating” or “treatment” refers tomodulating the disease or disorder, either physically, (e.g.,stabilization of a discernible symptom), physiologically, (e.g.,stabilization of a physical parameter), or both. In yet anotherembodiment, “treat”, “treating” or “treatment” refers to preventing ordelaying the onset or development or progression of the disease ordisorder.

As used herein, a subject is “in need of” a treatment if such subjectwould benefit biologically, medically or in quality of life from suchtreatment.

As used herein, the term “a,” “an,” “the” and similar terms used in thecontext of the present invention (especially in the context of theclaims) are to be construed to cover both the singular and plural unlessotherwise indicated herein or clearly contradicted by the context.

All methods described herein can be performed in any suitable orderunless otherwise indicated herein or otherwise clearly contradicted bycontext. The use of any and all examples, or exemplary language (e.g.“such as”) provided herein is intended merely to better illuminate theinvention and does not pose a limitation on the scope of the inventionotherwise claimed.

Any asymmetric atom (e.g., carbon or the like) of the compound(s) of thepresent invention can be present in racemic or enantiomericallyenriched, for example the (R)-, (S)- or (R,S)-configuration. In certainembodiments, each asymmetric atom has at least 50% enantiomeric excess,at least 60% enantiomeric excess, at least 70% enantiomeric excess, atleast 80% enantiomeric excess, at least 90% enantiomeric excess, atleast 95% enantiomeric excess, or at least 99% enantiomeric excess inthe (R)- or (S)-configuration. Substituents at atoms with unsaturateddouble bonds may, if possible, be present in cis-(Z)- or trans-(E)-form.

Accordingly, as used herein a compound of the present invention can bein the form of one of the possible isomers, rotamers, atropisomers,tautomers or mixtures thereof, for example, as substantially puregeometric (cis or trans) isomers, diastereomers, optical isomers(antipodes), racemates or mixtures thereof.

Any resulting mixtures of isomers can be separated on the basis of thephysicochemical differences of the constituents, into the pure orsubstantially pure geometric or optical isomers, diastereomers,racemates, for example, by chromatography and/or fractionalcrystallization.

Any resulting racemates of final products or intermediates can beresolved into the optical antipodes by known methods, e.g., byseparation of the diastereomeric salts thereof, obtained with anoptically active acid or base, and liberating the optically activeacidic or basic compound. In particular, a basic moiety may thus beemployed to resolve the compounds of the present invention into theiroptical antipodes, e.g., by fractional crystallization of a salt formedwith an optically active acid, e.g., tartaric acid, dibenzoyl tartaricacid, diacetyl tartaric acid, di-O,O′-p-toluoyl tartaric acid, mandelicacid, malic acid or camphor-10-sulfonic acid. Racemic products can alsobe resolved by chiral chromatography, e.g., high pressure liquidchromatography (HPLC) using a chiral adsorbent.

Furthermore, the compounds of the present invention, including theirsalts, can also be obtained in the form of their hydrates, or includeother solvents used for their crystallization. The compounds of thepresent invention may inherently or by design form solvates withpharmaceutically acceptable solvents (including water); therefore, it isintended that the invention embrace both solvated and unsolvated forms.The term “solvate” refers to a molecular complex of a compound of thepresent invention (including pharmaceutically acceptable salts thereof)with one or more solvent molecules. Such solvent molecules are thosecommonly used in the pharmaceutical art, which are known to be innocuousto the recipient, e.g., water, ethanol, and the like. The term “hydrate”refers to the complex where the solvent molecule is water.

The compounds of the present invention, including salts, hydrates andsolvates thereof, may inherently or by design form polymorphs.

Compositions

In another aspect, the present invention provides a pharmaceuticalcomposition comprising a compound of the present invention, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier. In a further embodiment, the composition comprisesat least two pharmaceutically acceptable carriers, such as thosedescribed herein. For purposes of the present invention, unlessdesignated otherwise, solvates and hydrates are generally consideredcompositions. Preferably, pharmaceutically acceptable carriers aresterile. The pharmaceutical composition can be formulated for particularroutes of administration such as oral administration, parenteraladministration, and rectal administration, etc. In addition, thepharmaceutical compositions of the present invention can be made up in asolid form (including without limitation capsules, tablets, pills,granules, powders or suppositories), or in a liquid form (includingwithout limitation solutions, suspensions or emulsions). Thepharmaceutical compositions can be subjected to conventionalpharmaceutical operations such as sterilization and/or can containconventional inert diluents, lubricating agents, or buffering agents, aswell as adjuvants, such as preservatives, stabilizers, wetting agents,emulsifiers and buffers, etc. Typically, the pharmaceutical compositionsare tablets or gelatin capsules comprising the active ingredienttogether with one or more of:

a) diluents, e.g., lactose, dextrose, sucrose, mannitol, sorbitol,cellulose and/or glycine;

b) lubricants, e.g., silica, talcum, stearic acid, its magnesium orcalcium salt and/or polyethyleneglycol; for tablets also

c) binders, e.g., magnesium aluminum silicate, starch paste, gelatin,tragacanth, methylcellulose, sodium carboxymethylcellulose and/orpolyvinylpyrrolidone; if desired

d) disintegrants, e.g., starches, agar, alginic acid or its sodium salt,or effervescent mixtures; and

e) absorbents, colorants, flavors and sweeteners.

Tablets may be either film coated or enteric coated according to methodsknown in the art.

Suitable compositions for oral administration include an effectiveamount of a compound of the invention in the form of tablets, lozenges,aqueous or oily suspensions, dispersible powders or granules, emulsion,hard or soft capsules, or syrups or elixirs. Compositions intended fororal use are prepared according to any method known in the art for themanufacture of pharmaceutical compositions and such compositions cancontain one or more agents selected from the group consisting ofsweetening agents, flavoring agents, coloring agents and preservingagents in order to provide pharmaceutically elegant and palatablepreparations. Tablets may contain the active ingredient in admixturewith nontoxic pharmaceutically acceptable excipients which are suitablefor the manufacture of tablets. These excipients are, for example, inertdiluents, such as calcium carbonate, sodium carbonate, lactose, calciumphosphate or sodium phosphate; granulating and disintegrating agents,for example, corn starch, or alginic acid; binding agents, for example,starch, gelatin or acacia; and lubricating agents, for example magnesiumstearate, stearic acid or talc. The tablets are uncoated or coated byknown techniques to delay disintegration and absorption in thegastrointestinal tract and thereby provide a sustained action over alonger period. For example, a time delay material such as glycerylmonostearate or glyceryl distearate can be employed. Formulations fororal use can be presented as hard gelatin capsules wherein the activeingredient is mixed with an inert solid diluent, for example, calciumcarbonate, calcium phosphate or kaolin, or as soft gelatin capsuleswherein the active ingredient is mixed with water or an oil medium, forexample, peanut oil, liquid paraffin or olive oil.

Certain injectable compositions are aqueous isotonic solutions orsuspensions, and suppositories are advantageously prepared from fattyemulsions or suspensions. Said compositions may be sterilized and/orcontain adjuvants, such as preserving, stabilizing, wetting oremulsifying agents, solution promoters, salts for regulating the osmoticpressure and/or buffers. In addition, they may also contain othertherapeutically valuable substances. Said compositions are preparedaccording to conventional mixing, granulating or coating methods,respectively, and contain about 0.1-75%, or contain about 1-50%, of theactive ingredient.

Suitable compositions for transdermal application include an effectiveamount of a compound of the invention with a suitable carrier. Carrierssuitable for transdermal delivery include absorbable pharmacologicallyacceptable solvents to assist passage through the skin of the host. Forexample, transdermal devices are in the form of a bandage comprising abacking member, a reservoir containing the compound optionally withcarriers, optionally a rate controlling barrier to deliver the compoundof the skin of the host at a controlled and predetermined rate over aprolonged period of time, and means to secure the device to the skin.

Suitable compositions for topical application, e.g., to the skin andeyes, include aqueous solutions, suspensions, ointments, creams, gels orsprayable formulations, e.g., for delivery by aerosol or the like. Suchtopical delivery systems will in particular be appropriate for dermalapplication, e.g., for the treatment of skin cancer, e.g., forprophylactic use in sun creams, lotions, sprays and the like. They arethus particularly suited for use in topical, including cosmetic,formulations well-known in the art. Such may contain solubilizers,stabilizers, tonicity enhancing agents, buffers and preservatives.

As used herein a topical application may also pertain to an inhalationor to an intranasal application. They may be conveniently delivered inthe form of a dry powder (either alone, as a mixture, for example a dryblend with lactose, or a mixed component particle, for example withphospholipids) from a dry powder inhaler or an aerosol spraypresentation from a pressurised container, pump, spray, atomizer ornebuliser, with or without the use of a suitable propellant.

The compounds of formula I in free form or in pharmaceuticallyacceptable salt form, exhibit valuable pharmacological properties, e.g.BET protein modulating properties, e.g. as indicated in tests asprovided in the next sections, and are therefore indicated for therapyor for use as research chemicals, e.g. as tool compounds.

Having regard to their activity as BET inhibitors, compounds of theformula (I) in free or pharmaceutically acceptable salt form, are usefulin the treatment of conditions which are mediated by the activity of BETproteins, such as cancer, and/or that are responsive (meaning especiallyin a therapeutically beneficial way) to inhibition of a BET protein,most especially a disease or disorder as mentioned herein below.

Compounds of the invention are believed to be useful in the treatment ofdiseases or disorders such as cancer. In particular, such cancersinclude benign or malignant tumours, a soft tissue sarcoma or a sarcomasuch as liposarcoma, rhabdomyosarcoma or bone cancer, e.g. osteosarcoma,a carcinoma, such as of the brain, kidney, liver, adrenal gland,bladder, breast, gastric, ovary, colon, rectum, prostate, pancreas, lung(including small cell lung cancer), vagina or thyroid, a glioblastoma,meningioma, glioma, mesothelioma, a neuroendocrine tumor such asneuroblastoma, a multiple myeloma, a gastrointestinal cancer, especiallycolon carcinoma or colorectal adenoma, a tumor of the head and neck, amelanoma, a prostate hyperplasia, a neoplasia, a neoplasia of epithelialcharacter, a neoplasia originating from blood or bone marrow, a leukemiasuch as acute myeloid leukemia (AML) or acute lymphoblastic leukemia(ALL) or B-cell chronic lymphocytic leukemia, a lymphoma, such as of B-or T-cell origin, such as diffuse large B cell lymphoma (DLBCL), NUTmidline carcinoma or any other neoplasia with chromosomal rearrangementsof the BET genes, and metastases in other organs. In particular,compounds of the invention are believed to be useful in a cancerselected from a neoplasia originating from blood or bone marrow; aleukemia such as acute myeloid leukemia (AML) or acute lymphoblasticleukemia (ALL) or B-cell chronic lymphocytic leukemia; a lymphoma, suchas of B- or T-cell origin, such as diffuse large B cell lymphoma(DLBCL); NUT midline carcinoma or any other neoplasia with chromosomalrearrangements of the BET genes, a neuroendocrine tumor such asneuroblastoma; a multiple myeloma; a lung cancer (including small celllung cancer); and a colon cancer.

Compounds of the invention may also be of use in the treatment ofatherosclerosis, coronary artery disease, dyslipidemia, diabetes, andother cardiovascular diseases, and/or as antiviral agents.

Thus, as a further embodiment, the present invention provides the use ofa compound of formula (I) or a salt thereof, in therapy. In a furtherembodiment, the therapy is selected from a disease which may be treatedby inhibition of BET proteins. In another embodiment, the disease is acancer disease selected from the afore-mentioned list.

Thus, as a further embodiment, the present invention provides a compoundof formula (I) or a salt thereof, for use in therapy. In a furtherembodiment, the therapy is selected from a disease which may be treatedby inhibition of a BET protein. In another embodiment, the disease is acancer disease selected from the afore-mentioned list.

In another embodiment, the invention provides a method of treating adisease which is treated by inhibition of a BET protein, comprisingadministration of a therapeutically acceptable amount of a compound offormula (I) or salt thereof. In a further embodiment, the disease is acancer disease selected from the afore-mentioned list.

Thus, as a further embodiment, the present invention provides the use ofa compound of formula (I) or salt thereof, for the manufacture of amedicament. In a further embodiment, the medicament is for treatment ofa disease which may be treated by inhibition of a BET protein. Inanother embodiment, the disease is a cancer disease selected from theafore-mentioned list.

The pharmaceutical composition or combination of the present inventioncan be in unit dosage of about 1-1000 mg of active ingredient(s) for asubject of about 50-70 kg, or about 1-500 mg or about 1-250 mg or about1-150 mg or about 0.5-100 mg, or about 1-50 mg of active ingredients.The therapeutically effective dosage of a compound, the pharmaceuticalcomposition, or the combinations thereof, is dependent on the species ofthe subject, the body weight, age and individual condition, the disorderor disease or the severity thereof being treated. A physician, clinicianor veterinarian of ordinary skill can readily determine the effectiveamount of each of the active ingredients necessary to prevent, treat orinhibit the progress of the disorder or disease.

The above-cited dosage properties are demonstrable in vitro and in vivotests using advantageously mammals, e.g., mice, rats, dogs, monkeys orisolated organs, tissues and preparations thereof. The compounds of thepresent invention can be applied in vitro in the form of solutions,e.g., aqueous solutions, and in vivo either enterally, parenterally,advantageously intravenously, e.g., as a suspension or in aqueoussolution. The dosage in vitro may range between about 10⁻³ molar and10⁻⁹ molar concentrations. A therapeutically effective amount in vivomay range depending on the route of administration, between about0.1-500 mg/kg, or between about 1-100 mg/kg.

The compound of the present invention may be administered eithersimultaneously with, or before or after, one or more other therapeuticagent. The compound of the present invention may be administeredseparately, by the same or different route of administration, ortogether in the same pharmaceutical composition as the other agents. Atherapeutic agent is, for example, a chemical compound, peptide,antibody, antibody fragment or nucleic acid, which is therapeuticallyactive or enhances the therapeutic activity when administered to apatient in combination with a compound of the invention.

Combinations

In one embodiment, the invention provides a product comprising acompound of formula (I) and at least one other therapeutic agent as acombined preparation for simultaneous, separate or sequential use intherapy. In one embodiment, the therapy is the treatment of a disease orcondition mediated by a BET protein. Products provided as a combinedpreparation include a composition comprising the compound of formula (I)and the other therapeutic agent(s) together in the same pharmaceuticalcomposition, or the compound of formula (I) and the other therapeuticagent(s) in separate form, e.g. in the form of a kit.

In one embodiment, the invention provides a pharmaceutical compositioncomprising a compound of formula (I) and another therapeutic agent(s).Optionally, the pharmaceutical composition may comprise apharmaceutically acceptable carrier, as described above.

In one embodiment, the invention provides a kit comprising two or moreseparate pharmaceutical compositions, at least one of which contains acompound of formula (I). In one embodiment, the kit comprises means forseparately retaining said compositions, such as a container, dividedbottle, or divided foil packet. An example of such a kit is a blisterpack, as typically used for the packaging of tablets, capsules and thelike.

The kit of the invention may be used for administering different dosageforms, for example, oral and parenteral, for administering the separatecompositions at different dosage intervals, or for titrating theseparate compositions against one another. To assist compliance, the kitof the invention typically comprises directions for administration.

In the combination therapies of the invention, the compound of theinvention and the other therapeutic agent may be manufactured and/orformulated by the same or different manufacturers. Moreover, thecompound of the invention and the other therapeutic may be broughttogether into a combination therapy: (i) prior to release of thecombination product to physicians (e.g. in the case of a kit comprisingthe compound of the invention and the other therapeutic agent); (ii) bythe physician themselves (or under the guidance of the physician)shortly before administration; (iii) in the patient themselves, e.g.during sequential administration of the compound of the invention andthe other therapeutic agent.

Accordingly, the invention provides the use of a compound of formula (I)for treating a disease or condition mediated by a BET protein, whereinthe medicament is prepared for administration with another therapeuticagent. The invention also provides the use of another therapeutic agentfor treating a disease or condition mediated by a BET protein, whereinthe medicament is administered with a compound of formula (I).

The invention also provides a compound of formula (I) for use in amethod of treating a disease or condition mediated by a BET protein,wherein the compound of formula (I) is prepared for administration withanother therapeutic agent. The invention also provides anothertherapeutic agent for use in a method of treating a disease or conditionmediated by a BET protein, wherein the other therapeutic agent isprepared for administration with a compound of formula (I). Theinvention also provides a compound of formula (I) for use in a method oftreating a disease or condition mediated by a BET protein, wherein thecompound of formula (I) is administered with another therapeutic agent.The invention also provides another therapeutic agent for use in amethod of treating a disease or condition mediated by a BET protein,wherein the other therapeutic agent is administered with a compound offormula (I).

The invention also provides the use of a compound of formula (I) fortreating a disease or condition mediated by a BET protein, wherein thepatient has previously (e.g. within 24 hours) been treated with anothertherapeutic agent. The invention also provides the use of anothertherapeutic agent for treating a disease or condition mediated by a BETprotein, wherein the patient has previously (e.g. within 24 hours) beentreated with a compound of formula (I).

In one embodiment, the other therapeutic agent is an anticancer agent.

In a further embodiment, the other therapeutic agent is a modulator of atarget in the field of epigenetics, such as an inhibitor of histonedeacetylase (HDAC), or an inhibitor of histone methyltransferase (HMT).

Generic Schemes

Typically, the compounds of formula (I) can be prepared according to theSchemes provided infra.

Compounds of formula (I), wherein A is

and R¹, R², R³, R⁴, R⁵ and R⁶ are as defined in Embodiment 1, may beprepared as described in Scheme 1.

wherein

LG is a suitable leaving group, such as mesylate;

PG is a suitable acid protecting group, such as methyl; and

M is a suitable metal, such as Li or Na.

Scheme 1 illustrates one method for preparing compounds of the invention(e.g. Example 1-3). A 3-substituted 2-hydrazinyl-5-nitropyridinederivative is acylated with the corresponding acetic acid anhydridederivative at 0° C.-25° C. in tetrahydrofurane or dioxane. The in situacylated derivative is converted at elevated temperature, usuallybetween 100-150° C., into the 3,8-di-substituted6-nitro-[1,2,4]triazolo[4,3-a]pyridine derivative, which upon reductionof the nitro group by catalytic hydrogenation, with 10% Pd—C 40-50° C.as the preferred catalytic system, in an appropiate solvent (methanol,ethanol, acetic acid) provided the 3,8-disubstituted[1,2,4]triazolo[4,3-a]pyridin-6-amine. Conversion of the secondaryalcohol of the corresponding 2-aryl-2-hydroxy-acetate derivative into aleaving group, for example with (a) methanesulfonyl chloride ormethanesulfonic anhydride in the presence of an organic base such aspyridine (together with a catalytic amount of 4-dimethylaminopyridine)or triethylamine or (b) 1-chloro-N,N,2-trimethylpropenylamine, followedby reaction with 3,8-disubstituted[1,2,4]triazolo[4,3-a]-pyridin-6-amineat temperatures between 0° C. and 50° C. results in the formation of thesecondary amine derivative. Alternatively, the the3,8-disubstituted[1,2,4]triazolo[4,3-a]pyridin-6-amine is converted intothe corresponding 6-azido-3,8-disubstituted1,2,4]triazolo[4,3-a]-pyridine with trimethylsilyl azide in acetonitrilein the presence of tert-butylnitrite at a temperature between 0° C. and20° C. Reduction of the azide intermediate in the presence of a4-substituted phenyl-2-oxoacetate with triphenylphosphine at atemperature between 20 and 100° C. followed by reduction of thegenerated imino-acetate with isopropanol-water in the presence of[Ru(CO)₂(Ph₄C₄CO)]₂ at elevated temperature, optimally between 80 to120° C., afforded the secondary amine intermediate. Sequent acylationwith a beta-keto-thioester derivative in the presence of silver(I)trfluoroacetate at ambient temperature results in the formation of thebeta-keto-amide derivative. The required beta-keto-thioester isgenerated from the corresponding S-pyridin-2-yl carbothioate derivativeand S-tert-butyl ethanethioate in the presence of a strong base (LiHMDS,NaHMDS) at low temperature. Claisen condensation of the beta-keto-amideto the cyclized beta-diketone can be effected under basic conditions (a)either with CsF in DMF at a temperature between 20° C. and 100° C. or(b) with sodium ethoxide in EtOH at elevated temperature. The finalpyrazolo-pyrrolidinone derivative is generated by condensation of thebeta-diketone derivative with the corresponding R⁴-containing hydrazine.Preferred reaction conditions for the condensation step are an alcoholicsolvent and temperatures between 80-130° C. in the microwave.

Alternatively, compounds of formula (I), wherein A, R¹, R², R³, R⁴, R⁵and R⁶ are as defined in Embodiment 1, may be prepared as described inScheme 2.

wherein PG is as defined for Scheme 1 and X is halo.

Scheme 2 illustrates a modification of the method shown in Scheme 1 forpreparing compounds of the invention (e.g. Examples 4-6). This method issimilar to the one described in Scheme 1 except that theR¹-/R⁶-containing bicyclic heteroaryl fragment is introduced by Chan-Lamor palladium-catalyzed C—N coupling. The 2-aryl-amino-ester derivativeis reacted with the corresponding beta-keto-thioester in the presence ofsilver(I) trifluoroacetate at ambient temperature to provide theketo-amide derivative. Cylization to the lactam and subsequentcondensation to the N5-unsubstituted5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one intermediate is carried outby the same methodology as described in Scheme 1. The lactamintermediate is arylated with the corresponding bicyclicheteroaryl-halide and an appropriate metal catalyst, for example aCu-salt, preferably CuI, and a base such as K₂CO₃, Cs₂CO₃ or K₃PO₄, inan appropriate solvent such as dioxane or toluene at elevatedtemperatures, preferable between 80-120° C. Alternatively, Pd-catalyzedC—N bond forming conditions are applied, preferably Pd₂(dba)₃ andXantphos together with Cs₂CO₃as base in dioxane at 90-120° C.

The invention further includes any variant of the present processes, inwhich an intermediate product obtainable at any stage thereof is used asstarting material and the remaining steps are carried out, or in whichthe starting materials are formed in situ under the reaction conditions,or in which the reaction components are used in the form of their saltsor optically pure material. Compounds of the invention and intermediatescan also be converted into each other according to methods generallyknown to those skilled in the art.

Synthetic Methods

The following examples are intended to illustrate the invention and arenot to be construed as being limitations thereon. Temperatures are givenin degrees Celsius. If not mentioned otherwise, all evaporations areperformed under reduced pressure, typically between about 15 mm Hg and100 mm Hg (=20-133 mbar). The structure of final products, intermediatesand starting materials is confirmed by standard analytical methods,e.g., microanalysis and spectroscopic characteristics, e.g., MS, IR,NMR. Abbreviations used are those conventional in the art.

All starting materials, building blocks, reagents, acids, bases,dehydrating agents, solvents, and catalysts utilized to synthesis thecompounds of the present invention are either commercially available orcan be produced by organic synthesis methods known to one of ordinaryskill in the art. Further, the compounds of the present invention can beproduced by organic synthesis methods known to one of ordinary skill inthe art as shown in the following examples.

Abbreviations

ACN acetonitrile

Ac₂O acetic acid anhydride

aq. aqueous

Ar argon

Boc tert-butoxycarbonyl

Brine saturated (at rt) sodium chloride solution

br. s. broad singlet

CH₂Cl₂ dichloromethane

CuI copper(I) iodide

d doublet

DEA diethylamine

DIPEA diisopropyl ethyl amine

DMAP 4-dimethylaminopyridine

DMF N,N-dimethylformamide

DMSO dimethylsulfoxide

ESI-MS electrospray ionisation mass spectrometry

EtOAc ethyl acetate

EtOH ethanol

h hour(s)

H₂O water

K₂CO₃ potassium carbonate

K₃PO₄ potassium phosphate

LC-MS liquid chromatography mass spectrometry

LiHMDS lithium hexamethyldisilazide

MeOH methanol

MgSO₄ magnesium sulfate

m multiplet

min minute(s)

mL milliliter(s)

MS mass spectrometry

Ms₂O methanesulfonic anhydride

MW microwave

NaHCO₃ sodium bicarbonate

NaOH sodium hydroxide

Na₂SO₄ sodium sulfate

NH₄Cl ammonium chloride

NMR nuclear magnetic resonance

Pd₂(dba)₃ tris(dibenzylideneacetone)dipalladium(0)

POCl₃ phosphoroxychloride

ppm parks per million

R_(f) ratio of fronts

rt (or RT) room temperature

s singlet

sat. saturated

scCO₂ supercritical carbon dioxide

SFC supercritical fluid chromatography

t triplet

t_(R) time of retention

TFA trifluoroacetic acid

THF tetrahydrofuran

UPLC ultra performance liquid chromatography

Xantphos 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene

UPLC Method:

UPLC 1: Column: Acquity UPLC HSS T3 C18, 1.7 μm 2.1×50 mm, Flow: 1.0mL/min. Column temperature: 30° C. Gradient: 5% to 100% B in 1.5 min,100% B for 1 min, A=water+0.1% TFA, B=ACN+0.1% TFA

LC-MS Method:

LC-MS 1:

Column: Waters Acquity HSS T3, 1.8 μm, 2.1×50 mm, oven at 60° C. Flow:1.0 mL/min. Gradient: 5% to 98% B in 1.40 min, then 98% B for 0.40 min,98% to 5% B in 0.10 min, 5% B for 0.10 min; A=water+0.05% formicacid+3.75 mM ammonium acetate, B=ACN+0.04% formic acid. Detection UV/VIS(DAD), ESI (+/−). Mass spectrometer range: 100-1200 Da.

LC-MS 2:

Column: Waters Acquity HSS T3, 1.8 μm, 2.1×50 mm, oven at 60° C. Flow:1.0 mL/min. Gradient: 5% to 98% B in 1.40 min, then 98% B for 0.40 min,98% to 5% B in 0.10 min, 5% B for 0.10 min; A=water+0.05% formicacid+3.75 mM ammonium acetate, B=acetonitrile+0.04% formic acid.Detection UV/VIS (DAD), ESI (+/−). Mass spectrometer range: 100-1200 Da.

EXAMPLE 16-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

To a solution of5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)pyrrolidine-2,4-dione(0.8 mmol, 339 mg) in MeOH (2 mL) was added methyl-hydrazine (2.4 mmol,111 mg) and the reaction mixture was stirred for 3.5 h at 110° C. in theMW. The reaction mixture was concentrated and the residual oil waspurified by silica gel column chromatography (hexane/EtOAc/MeOH 80:20:4to 0:5:1) to afford the title product (218 mg, 60% yield) as a lightyellow foam. t_(R): 0.822 min (UPLC 1); t_(R): 0.90 min (LC-MS 1);ESI-MS: 433/435 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm0.79-1.19 (m, 4H) 1.88-2.10 (m, 1H) 2.44 (s, 3H) 2.62 (s, 3H) 3.47 (s,3H) 6.61 (s, 1H) 7.29 (s, 1H) 7.41 (s, 4H) 8.36 (s, 1H).

Step 1.1: ethyl2-(4-chlorophenyl)-2-((3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)-acetate

To a solution of ethyl 2-(4-chlorophenyl)-2-hydroxyacetate (2.146 g, 10mmol) and NEt₃ (6.97 mL, 50.0 mmol) in CH₂Cl₂ (40 mL) was added at 0° C.Ms₂O (3.136 g, 18.00 mmol). The reaction mixture was stirred for 0.5 hat 0° C. To the reaction mixture was added3,8-dimethyl-[1,2,4]-triazolo[4,3-a]pyridin-6-amine (1.946 g, 12.00mmol) and the reaction mixture was allowed to warm to RT. After heatingfor 3 h at 40-45° C., the reaction mixture was added to sat. NaHCO₃solution and EtOAc and the product was extracted with EtOAc. Combinedextracts were washed with a small amount of brine, dried over MgSO₄,filtered and concentrated. The crude product was purified by silica gelcolumn chromatography (hexane/EtOAc/MeOH 75:25:3 to 0:50:5) to affordthe title product (1.15 g, 30% yield) as a beige solid. t_(R): 0.856 min(UPLC 1); t_(R): 0.92 min (LC-MS 1); ESI-MS: 359/361 [M+H]⁺ (LC-MS 1);R_(f)=0.30 (EtOAc/MeOH 9:1); ¹H NMR (400 MHz, CDCl₃) δ ppm 1.17 (t,J=7.2 Hz, 3H) 2.42 (s, 3H) 2.52 (s, 3H) 4.04-4.15 (m, 1H) 4.16-4.26 (m,1H) 4.83 (m, 1H) 6.38 (s, 1H) 6.61 (s, 1H) 7.30 (d, J=8.6 Hz, 2H) 7.38(d, J=8.6 Hz, 2H).

Step 1.2: ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate

To a solution of ethyl2-(4-chlorophenyl)-2-((3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-amino)acetate(851 mg, 1.5 mmol) and S-tert-butyl 3-cyclopropyl-3-oxopropanethioate(390 mg, 1.95 mmol, Step 1.4) in THF (15 mL) was added silvertrifluoroacetate (431 mg, 1.95 mmol) at RT. The resulting dark brownsolution was stirred for 1 h at RT. The reaction mixture was filteredover Celite, the filtrate concentrated and the resulting crude productwas purified by silica gel column chromatography(hexane/EtOAc/MeOH90:10:1 to 0:100:10 containing 0.1% NEt₃) to afford the title product(604 mg, 83% yield) as a yellow foam. t_(R): 0.870 min (UPLC 1); t_(R):0.95 min (LC-MS 1); ESI-MS: 465/467 [M−H]⁺ (LC-MS 1).

Step 1.3:5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)pyrrolidine-2,4-dione

To a solution of ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate(560 mg, 1.20 mmol) in DMF (10 mL) was added under Ar CsF (370 mg, 2.4mmol) at RT and the resulting dark brown solution was stirred for 14 hat 60° C. The reaction mixture was concentrated and to the residue wasadded to cold 1N H₂SO₄. The product was extracted with EtOAc. Combinedextracts were washed with brine, dried over MgSO₄, filtered,concentrated and dried at 60° C. to provide the title product (101 mg,18%) as a yellow foam. t_(R): 0.881 min (UPLC 1); t_(R): 0.77 min (LC-MS1); ESI-MS: 423/425 [M+H]⁺ (LC-MS 1).

Step 1.4: S-pyridin-2-yl cyclopropanecarbothioate

To a solution of pyridine-2-thiol (29.2 g, 260 mmol) in THF (260 mL) wasadded under Ar the cyclopropanecarbonyl chloride (27.7 g, 260 mmol) atRT and the reaction mixture was stirred for 0.5 h at 25° C. Theprecipitated HCl-salt was filtered off and washed with Et₂O-hexane 1:4and hexane. The light yellow precipitate was added to sat. NaHCO₃solution and EtOAc and the product was extracted with EtOAc. Combinedextracts were washed with brine, dried over MgSO₄, filtered andconcentrated to provide the title compound (37.3 g, 80% yield) as ayellow oil. t_(R): 0.79 min (LC-MS 1); ESI-MS: 180 [M+H]⁺ (LC-MS 1); NMR(400 MHz, CDCl₃) δ ppm 0.83-1.03 (m, 2H) 1.09-1.28 (m, 2H) 1.91-2.16 (m,1H) 7.10-7.28 (m, 1H) 7.60-7.74 (m, 1H) 8.55 (dd, J=4.8, 1.1 Hz, 1H).

Step 1.5: S-tert-butyl 3-cyclopropyl-3-oxopropanethioate

To a solution of S-pyridin-2-yl cyclopropanecarbothioate (16.5 g, 92mmol) in THF (250 mL) was 15 added under Ar a 1M LiHMDS solution in THF(229 mL, 229 mmol) at <−70° C. To the reaction mixture was added asolution of S-tert-butyl ethanethioate (14.0 mL, 96 mmol) in THF (30 mL)below −70° C. After stirring for 0.5 h at −78° C. the reaction mixturewas slowly warmed up to −50° C. over a period of 1 h. After completion,the reaction mixture was added to 300 mL cold 1N H₂SO₄ and ice and theproduct was extracted with EtOAc. Combined extracts were washed withbrine, dried over MgSO₄, filtered and concentrated. The crude oil wasredissolved in Et₂O, kept at 0° C. for 14 h, filtered through a shortplug of silicagel and concentrated again to provide the title product(18.3 g, 95% yield) as a yellow oil. t_(R): 1.089 min (UPLC 1); t_(R):1.06 min (LC-MS 1); ESI-MS: 201 [M+H]⁺ (LC-MS 1); R_(f)=0.59 (EtOAc);NMR (400 MHz, CDCl₃) δ ppm 0.80 (m, 2H) 0.91-0.99 (m, 2H) 1.33 (s, 9H)1.92 (m, 1H) 3.53 (s, 2H).

EXAMPLE 2(R)-6-4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound (69 mg, 34% yield) was obtained enantiomerically pure(>99% ee) as a white solid after chiral preparative chromatography(system: SFC-PicLab-Prep 100; column: Chiralpak AD-H 50×250 mm; mobilephase: scCO₂/MeOH 40:60 (isocratic); flow: 150 g/min; detection UV: 245nm) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 1) (210 mg, 0.46 mmol) and trituration of the resulting residuein Et₂O. t_(R): 0.827 min (UPLC 1); t_(R): 0.90 min (LC-MS 1); ESI-MS:433/455 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 0.79-1.19 (m,4H) 1.88-2.10 (m, 1H) 2.44 (s, 3H) 2.62 (s, 3H) 3.47 (s, 3H) 6.61 (s,1H) 7.29 (s, 1H) 7.41 (s, 4H) 8.36 (s, 1H). The second enantiomer,(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,was obtained via the same separation as a white solid (75 mg, 36% yield)in enantiomerically pure form (99% ee).

EXAMPLE 36-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

To a solution of ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3-(difluoromethyl)-8-methyl-[1,2,4]-triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate(540 mg, 0.941 mmol) in MeOH (5 mL) was added methylhydrazine (0.15 mL,2.82 mmol) and the reaction mixture was heated in the MW for 3 h at 100°C. and for 2 h at 120° C. The reaction mixture was concentrated and thecrude product was purified by silica gel column chromatography(hexane/EtOAc/MeOH 90:10:1 to 0:100:10). The resulting residue wasfurther purified by SFC (Reprosil70-NH₂ (250×30 mm, 5 μm), gradient:11-16% B in 6 min, A: scCO₂, B: MeOH; flow: 100 mL/min) to afford thetitle product (255 mg, 30% yield) after trituration in Et₂O as a whitesolid. t_(R): 1.046 min (UPLC 1); t_(R): 1.03 min (LC-MS 1); ESI-MS:469/471 [M+H]⁺ (LC-MS 1); R_(f)=0.24 (EtOAc/MeOH 9:1); ¹H NMR (400 MHz,DMSO-d₆) δ ppm 0.90-1.15 (m, 4H) 1.91-2.10 (m, 1) 2.52 (s, 3H) 3.34 (s,3H) 6.71 (s, 1H) 7.38-7.48 (m, 4H) 7.59 (s, 1H) 7.71 (t, J=51.2 Hz, 1H)8.65 (s, 1H).

Step 3.1:3-(difluoromethyl)-8-methyl-6-nitro-[1,2,4]triazolo[4,3-a]pyridine

To a solution of 2-hydrazinyl-3-methyl-5-nitropyridine (2 g, 11.9 mmol)in THF (50 mL) was added a solution of 2,2-difluoroacetic anhydride(1.68 mL, 13.08 mmol) in THF (2 mL) at 0° C. over a period of 0.5 h. Thereaction mixture was stirred for 0.5 h at 0° C. and the initially formed2,2-difluoro-N′-(3-methyl-5-nitropyridin-2-yl)acetohydrazide wassubsequently heated for 4 h at 140° C. in the MW. The reaction mixturewas concentrated and the crude product was purified by silica gel columnchromatography (hexane/CH₂Cl₂/MeOH 90:10:1 to 50:50:5) to provide thetitle product (2.31 g, 85% yield) as a brown solid. t_(R): 0.68 min(LC-MS 1); ESI-MS: 229 [M+H]⁺ (LC-MS 1); R_(f)=0.48 (hexane/EtOAc/MeOH50:50:5); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.69 (s, 3H) 7.77 (t, J=56.7Hz, 1H) 8.09 (s, 1H) 9.60 (s, 1H).

Step 3.2:3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine

A solution of3-(difluoromethyl)-8-methyl-6-nitro-[1,2,4]triazolo[4,3-a]pyridine (3.3g, 10.12 mmol) in MeOH (30 mL) was hydrogenated over 10% Pd/C (0.86 g)for 3 h at 50° C. and 1000 mbar H₂. The reaction mixture was filteredover Celite and the filtrate was concentrated. The crude product waspurified by silica gel column chromatography (hexane/CH₂Cl₂/MeOH100:100:5 to 0:100:5 containing 0.2% NEt₃) to provide the title product(1.05 g, 49% yield) as a white solid. t_(R): 0.46 min (LC-MS 1); ESI-MS:199 [M+H]⁺ (LC-MS 1); R_(f)=0.35 (CH₂Cl₂/MeOH 19:1); ¹H NMR (400 MHz,DMSO-d₆) δ ppm 2.52 (s, 3H) 5.41 (s, 2H) 6.95 (s, 1H) 7.61 (t, J=53.9Hz, 1H) 7.56 (s, 1H).

Step 3.3: ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)acetate

To a solution of ethyl 2-(4-chlorophenyl)-2-hydroxyacetate (890 mg, 4.15mmol) and NEt₃ (2.9 mL, 20.8 mmol) in dioxane (12 mL) was added at 0° C.Ms₂O (1.3 g, 7.46 mmol). The resulting reaction mixture was stirred for0.5 h at 0° C. To the reaction mixture was added3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine (986mg, 4.98 mmol) and the reaction mixture was heated in the MW for 1 h at160° C. The reaction mixture was added to sat. NaHCO₃ solution and EtOAcand the product was extracted with EtOAc. Combined extracts were washedwith a small amount of brine, dried over MgSO₄, filtered andconcentrated. The crude product was purified by silica gel columnchromatography (hexane/EtOAc/MeOH 90:10:1 to 50:50:5) to afford thetitle product (460 mg, 27% yield) as a reddish foam. t_(R): 1.07 min(LC-MS 1); ESI-MS: 395/397 [M+H]⁺ (LC-MS 1); R_(f)=0.40(hexane/EtOAc/MeOH 10:10:1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.15 (t,J=7.03 Hz, 3H) 2.53 (s, 3H) 4.07-4.12 (m 1H) 4.14-4.23 (m, 1H) 5.35 (d,J=8.1 Hz, 1H) 6.89 (d, J=8.1 Hz, 1H) 7.25 (s, 1H) 7.35 (s, 1H) 7.44-7.62(m, 5H).

Step 3.4: ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate

The title compound was prepared in analogy to the procedure described inStep 1.2 using ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate(Step 3.3) and S-tert-butyl 3-cyclopropyl-3-oxopropanethioate (Step1.5). t_(R): 1.04 min (LC-MS 1); ESI-MS: 503/505 [M−H]⁺ (LC-MS 1);R_(f)=0.30 (hexane/EtOAc/MeOH 10:10:1).

Step 3.5: ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate

The title compound was prepared in analogy to the procedure described inStep 1.3 using ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-N-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-oxopropanamido)acetate(Step 3.4). t_(R): 0.86 min (LC-MS 1); ESI-MS: 459/461 [M+H]⁺ (LC-MS 1).

EXAMPLE 46-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

To a suspension of6-(4-chlorophenyl)-3-cyclopropyl-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(170 mg, 0.512 mmol) and6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]-pyridine (151 mg, 0.666mmol) in dioxane was added under Ar CuI (48.8 mg, 0.256 mmol), K₃PO₄(218 mg, 1.025 mmol) and N-N′-dimethylethylenediamine (151 mg, 0.666mmol) and the reaction mixture was heated for 30 h at 110° C. Thereaction mixture was added to sat. NaHCO₃ solution containing some conc.aq. NH₃ and the product was extracted with EtOAc-MeOH 20:1. Combinedextracts were washed with brine, dried over MgSO₄, filtered andconcentrated. The crude product was purified by silica gel columnchromatography (hexane/EtOAc/MeOH 80:20:4 to 0:20:4). The resultingproduct was further purified by SFC (Propyl-pyridyl-urea (250×30 mm, 5μm), gradient: 15-10% B in 6 min, A: scCO₂, B: MeOH; flow: 100 mL/min)to afford the title product (65 mg, 26% yield) after trituration in Et₂Oas a white solid, t_(R): 0.863 min (UPLC 1); t_(R): 0.91 min (LC-MS 1);ESI-MS: 477/479 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, CDCl₃) δ ppm0.95-1.05 (m, 2H) 1.09-1.26 (m, 2H) 1.96-2.06 (m, 1H) 2.50 (s, 3H) 2.58(s, 3H) 3.28 (s, 3H) 3.44-3.67 (m, 3H) 3.88 -3.96 (m, 1H) 5.86 (s, 1H)6.82 (s, 1H) 7.13 (d, J=8.3 Hz, 2H) 7.27 (d, J=8.3 Hz, 2H) 7.98 (s, 1H).

Step 4.1: ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-3-oxopropanamido)acetate

To a solution of ethyl 2-amino-2-(4-chlorophenyl)acetate (8.08 g, 37.8mmol) and S-tert-butyl 3-cyclopropyl-3-oxopropanethioate (9.05 g, 45.4mmol, Step 1.5) in THF (100 mL) was added under Ar silvertrifluoroacetate (11.07 g, 49.1 mmol) at RT. The resulting dark brownsolution was stirred for 16 h at RT. The reaction mixture was filteredover Celite, the filtrate concentrated and the resulting crude productwas purified by silica gel column chromatography (hexane/EtOAc/MeOH80:20:4 to 0:20:4) to afford the title product (11.5 g, 94% yield) as alight brown oil. t_(R): 0.998 min (UPLC 1); t_(R): 0.98 min (LC-MS 1);ESI-MS: 322/324 [M−H]⁺ (LC-MS 1); R_(f)=0.63 (EtOAc); ¹H NMR (400 MHz,CDCl₃) δ ppm 0.98-1.31 (m, 7H) 1.95-2.05 (m, 1H) 3.54-3.73 (m, 2H)4.11-4.31 (m, 2H) 5.45-5.62 (m, 1H) 7.35 (s, 4H) 8.46 (br. s., 1H).

Step 4.2:5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione

The title compound was prepared in analogy to the procedure described inStep 1.3 using ethyl2-(4-chlorophenyl)-2-(3-cyclopropyl-3-oxopropanamido)acetate (Step 4.1).t_(R): 0.93 min (LC-MS 1); ESI-MS: 278/280 [M+H]⁺ (LC-MS 1); R_(f)=0.38(EtOAc/MeOH 9:1); ¹H NMR (400 MHz, DMSO-d6) δ ppm 1.05-1.34 (m, 5H) 2.81(br. s., 1H) 5.06 (s, 1H) 7.33 (d, J=8.4 Hz, 2H) 7.47 (d, J=8.4 Hz, 2H)9.34 (br. s., 1H).

Step 4.3:6-(4-chlorophenyl)-3-cyclopropyl-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione (Step4.2) and (2-methoxy-ethyl)hydrazine. t_(R): 0.87 min (LC-MS 1); ESI-MS:332/334 [M+H]⁺ (LC-MS 1), ¹H NMR (400 MHz, CDCl₃) δ ppm 0.96 (dd, J=8.4,2.2 Hz, 2H) 1.06-1.21 (m, 2H) 1.90-1.99 (m, 1H) 3.21 (s, 3H) 3.42 (dt,J=9.7, 3.5 Hz, 1H) 3.52 (td, J=9.6, 2.6 Hz, 1H) 3.61 (ddd, J=14.1, 9.5,3.8 Hz, 1H) 3.86 (dt, J=14.1, 3.2 Hz, 1H) 5.46 (s, 1H) 5.68 (s, 1H)7.14-7.19 (m, 2H) 7.24-7.34 (m, 2H).

EXAMPLE 56-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) and 6-bromo-8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridine(Step 5.3). t_(R): 0.86 min (LC-MS 1); ESI-MS: 449/451 [M+H]⁺ (LC-MS 1);R_(f)=0.31 (CH₂Cl₂/MeOH 10:1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 0.94-1.17(m, 4H) 1.93-2.08 (m, 1H) 2.60 (s, 3H) 3.48 (m, 3H) 3.92 (m, 3H) 6.66(s, 1H) 6.87 (s, 1H) 7.42 (s, 4H) 8.12 (s, 1H).

Step 5.1:6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione (Step4.2) and methylhydrazine. t_(R): 0.85 min (LC-MS 1); ESI-MS: 288/290[M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, CDCl₃) δ ppm 0.96 (dd, J=8.4, 2.5 Hz,2H) 1.11 (ddd, J=17.0, 5.1, 2.3 Hz, 3H) 1.90-2.00 (m, 1H) 3.40 (s, 3H)5.37 (s, 1H) 5.65 (s, 1H) 7.14 (d, J=8.4 Hz, 2H) 7.30 (d, J=8.4 Hz, 2H).

Step 5.2: N′-(5-bromo-3-methoxypyridin-2-yl)acetohydrazide

To a suspension of 5-bromo-2-hydrazinyl-3-methoxypyridine (505 mg, 2.3mmol) in dioxane (5 mL) was added Ac₂O (0.28 mL, 3.0 mmol) at 0-10° C.The reaction mixture was stirred for 0.5 h at RT. The reaction mixturewas poured onto ice-water and the product was extracted with EtOAc.Combined extracts were washed with a small amount of brine, dried overMgSO₄, filtered and concentrated to afford the title product (505 mg,84% yield) as a yellow solid. t_(R): 0.56 min (LC-MS 1); ESI-MS: 260/263[M+H]⁺ (LC-MS 1); R_(f)=0.34 (CH₂Cl₂/MeOH 10:1); ¹H NMR (400 MHz,DMSO-d₆) δ ppm 1.87 (s, 3H) 3.85 (s, 3H) 7.32 (d, J=1.8 Hz, 1H) 7.71 (d,J=1.8 Hz, 1H) 8.04 (d, J=2.3 Hz, 1H) 9.65 (d, J=2.2 Hz, 1H).

Step 5.3: 6-bromo-8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridine

To a suspension of N′-(5-bromo-3-methoxypyridin-2-yl)acetohydrazide (550mg, 1.672 mmol) and DIPEA (0.22 mL, 1.254 mmol) in ACN (5 mL) was addedunder Ar slowly POCl₃ (0.30 mL, 3.2 mmol). The reaction mixture washeated for 5 h at 90° C. The reaction mixture was slowly added to H₂O at40° C. and after careful neutralization with NaHCO₃ to pH 6.5 extractedwith EtOAc. Combined extracts were washed with a small amount of brine,dried over MgSO₄, filtered and concentrated to afford the title product(340 mg, 82% yield) as a yellow solid after trituration with Et₂O.t_(R): 0.57 min (LC-MS 1); ESI-MS: 242/244 [M+H]⁺ (LC-MS 1); R_(f)=0.39(CH₂Cl₂/MeOH 10:1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.66 (s, 3H) 4.00(s, 3H) 6.85 (s, 1H) 8.35 (s, 1H).

EXAMPLE 66-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

To a suspension of6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) (120 mg, 0.417 mmol),6-bromo-4-methoxy-1-methyl-1H-benzo[d][1,2,3]-triazole (Step 6.3) (151mg, 0.626 mmol) and Cs₂CO₃ (272 mg, 0.834 mmol) in dioxane was addedunder Ar Xantphos (48.3 mg, 0.083 mmol) and Pd₂(dba)₃ (38.2 mg, 0.042mmol) and the reaction mixture was heated for 16 h at 100° C. Thereaction mixture was filtered over Celite and the filtrate concentrated.The resulting residue was dissolved in CH₂Cl₂ and washed with H₂O, driedover Na2SO4, filtered and concentrated. The crude product was purifiedby SFC (Silica (250×30 mm, 5 μm), gradient: 19-24% B in 6 min, A: scCO₂,B: MeOH; flow: 100 mL/min) to afford the title product (121 mg, 64%yield) after trituration in Et₂O as a white solid. t_(R): 1.03 min(LC-MS 1); ESI-MS: 449/451 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δppm 0.97-1.18 (m, 4H) 1.99-2.06 (m, 1H) 3.48 (s, 3H) 3.97 (s, 3H)4.15-4.19 (m, 3H) 6.80 (s, 1H) 7.01 (d, J=1.2 Hz, 1H) 7.40 (d, J=8.3 Hz,2H) 7.44 (d, J=8.1 Hz, 2H) 7.50 (d, J=1.4 Hz, 1H).

Step 6.1: 5-bromo-3-methoxy-N-methyl-2-nitroaniline

To a solution of 5-bromo-1-fluoro-3-methoxy-2-nitrobenzene (5.5 g, 22.00mmol) in THF (44 mL) was added a 2M solution of methylamine in THF (44.0mL, 88 mmol) and the reaction mixture was heated at reflux for 2 h. Theformed precipitate of the cold reaction mixture was filtered off and thefiltrate was concentrated to provide the title product (5.6 g, 98%yield) as an orange solid.

Step 6.2: 5-bromo-3-methoxy-N1-methylbenzene-1,2-diamine

A solution of 5-bromo-3-methoxy-N-methyl-2-nitroaniline (8.84 g, 33.9mmol) in THF/MeOH 1:1 (400 mL) was hydrogenated over Raney-nickel (1.0g) for 21 h at RT and 1000 mbar H₂. The reaction mixture was filteredover Celite and the filtrate was concentrated to provide the titleproduct (7.92 g, 99% yield) as brown oil. t_(R): 0.90 min (LC-MS 1);ESI-MS: 231/233 [M+H]⁺ (LC-MS 1).

Step 6.3: 6-bromo-4-methoxy-1-methyl-1H-benzo[d][1,2,3]triazole

To a solution of 5-bromo-3-methoxy-N1-methylbenzene-1,2-diamine (7.8 g,33.8 mmol) in 8N HCl (42.2 mL, 338 mmol) was added dropwise a solutionof NaNO₂ (2.56 g, 37.1 mmol) in H₂O (25 mL) at 0° C. After the addition,the reaction mixture was stirred for 15 min at 0° C. and 30 min at RT.The reaction mixture was added to brine and the product was extractedwith EtOAc. Combined extracts were washed with brine, dried over Na₂SO₄,filtered and concentrated. The crude product was purified by silica gelcolumn chromatography (hexane/EtOAc 97:3 to 60:40) to provide the titleproduct (4.0 g, 49% yield) as a dark yellow solid. t_(R): 0.35 min(LC-MS 1); ESI-MS: 243/245 [M+H]⁺ (LC-MS 1); ¹H NMR (600 MHz, DMSO-d₆) δppm 4.04 (s, 3 H) 4.25 (s, 3 H) 6.99 (d, J=1.1 Hz, 1H) 7.75 (d, J=1.3Hz, 1H).

EXAMPLE 7(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% cc) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO₂/isopropanol 60:40(isocratic), flow: 50 mL/min) of the racemic mixture6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 3).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.23 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 60:40(isocratic), flow: 2.4 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 3.19 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 60:40(isocratic), flow: 2.4 mL/min; detection UV: 220 nm).

Example 86-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) and 6-bromo-1,4-dimethyl-1H-benzo[d][1,2,3]triazole (Step8.1). t_(R): 1.07 min (LC-MS 1); ESI-MS: 433/435 [M+H]⁺ (LC-MS 1);R_(f)=0.50 (EtOAc/MeOH 9:1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 0.97-1.12(m, 4H) 2.01 (m, 1H) 2.59 (s, 3H) 3.46 (s, 3H) 4.20 (s, 3H) 6.73 (s, 1H)7.33-7.44 (m, 4H) 7.74 (s, 1H).

Step 8.1: 5-bromo-N,3-dimethyl-2-nitroaniline

A solution of 5-bromo-1-fluoro-3-methyl-2-nitrobenzene (500 mg, 2.14mmol) and methylamine 2M in THF (5 mL, 10.0 mmol) was heated in themicrowave for 30 min at 100° C. The reaction mixture was concentratedunder reduced pressure to afford the title product (520 mg, 99% yield)as yellow solid. t_(R): 1.19 min (LC-MS 2); ESI-MS: no ionisation (LC-MS2).

Step 8.2: 5-bromo-N1,3-dimethylbenzene-1,2-diamine

To a solution of 5-bromo-N,3-dimethyl-2-nitroaniline (Step 8.1) (2.7 g,11.02 mmol) in THF (100 mL) and MeOH (100 mL) was added Raney Nickel(189 mg, 2.203 mmol) and the resulting mixture was stirred underhydrogen atmosphere at RT for 16 h. The reaction was filtered through apad of Celite and the resulting filtrate was concentrated under reducedpressure to afford the title product (2.5 g, 96% yield) as off-whitesolid. t_(R): 0.94 min (LC-MS 2); ESI-MS: 215/217 [M+H]⁺ (LC-MS 2).

Step 8.3: 6-bromo-1,4-dimethyl-1H-benzo[d][1,2,3]triazole

To a solution of 5-bromo-N¹,3-dimethylbenzene-1,2-diamine (Step 8.2)(2.5 g, 11.62 mmol) in HCl conc (15 mL, 494 mmol) was slowly added asolution of NaNO₂ (0.962 g, 13.95 mmol) in water (25 mL) at 0° C. Thereaction mixture was stirred for 2 h at RT, then basified with aq. NaOH.The precipitated solid was filtrated off, washed with water and driedunder reduced pressure to afford the title product (2.5 g, 86% yield) asbeige solid. t_(R): 0.93 min (LC-MS 2); ESI-MS: 226/228 [M+H]⁺ (LC-MS2).

Example 9(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% cc) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO₂/isopropanol 50:50(isocratic), flow: 40 mL/min) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 8).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 3.01 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 50:50(isocratic), flow: 2 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 5.65 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 50:50(isocratic), flow: 2 mL/min; detection UV: 220 nm).

Example 106-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxynicotinoyl)pyrrolidine-2,4-dione(Step 10.4) and hydrazine. t_(R): 0.96 min (LC-MS 1); ESI-MS: 486/488[M+H]⁺ (LC-MS 1); R_(f)=0.50 (CH₂Cl₂/MeOH 10:1); ¹H NMR (400 MHz,DMSO-d₆) δ ppm 2.46 (s, 3H) 2.64 (s, 3H) 4.07 (m, 3H) 6.68 (s, 1H) 7.26(dd, J=7.6, 4.9 Hz, 1H) 7.32-7.47 (m, 5H) 8.29 (dd, J=4.9, 1.9 Hz, 1H)8.51 (s, 1H) 9.03 (dd, J=7.5, 1.9 Hz, 1H).

Step 10.1: S-pyridin-2-yl2-methoxypyridine-3-carbothioate

To a solution of 2-methoxynicotinic acid (0.766 g, 5 mmol) and1,2-di(pyridin-2-yl)disulfane (1.124 g in THF (20 mL) was added underargon PPh₃ (1.337 g, 5 mmol) and the reaction mixture was stirred at 25°C. for 12 h. The reaction mixture was concentrated and the title productwas obtained after silica gel column chromatography (hexane/EtOAc 80:20to 50:50) (0.902 g, 72% yield) as a white solid. t_(R): 0.795 min (UPLC1); t_(R): 0.87 min (LC-MS 1); ESI-MS: 247 [M+H]⁺ (LC-MS 1); R_(f)=0.36(hexane/EtOAc 1:1); ¹H NMR (400 MHz, CDCl₃) δ ppm 8.61 (ddd, J=4.9, 1.9,0.9 Hz, 1H), 8.29 (dd, J=4.9, 2.0 Hz, 1H), 8.12 (dd, J=7.6, 2.0 Hz, 1H),7.76-7.62 (m, 2H), 7.26 (ddd, J=7.4, 4.8, 1.3 Hz, 1H), 6.95 (dd, J=7.6,4.9 Hz, 1H), 4.05 (s, 3H).

Step 10.2: S-tert-butyl 3-(2-methoxypyridin-3-yl)-3-oxopropanethioate

The title compound was prepared in analogy to the procedure described inStep 1.5 using 5-pyridin-2-yl 2-methoxypyridine-3-carbothioate (Step10.1) and S-tert-butyl ethanethioate. t_(R): 1.14 min (LC-MS 1); ESI-MS:268 [M−H]⁺ (LC-MS 1).

Step 10.3: ethyl2-(4-chlorophenyl)-2-(N-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-3-oxopropanamido)acetate

The title compound was prepared in analogy to the procedure described inStep 1.2 using ethyl2-(4-chlorophenyl)-2-((3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)acetate(Step 1.1) and S-tert-butyl3-(2-methoxypyridin-3-yl)-3-oxopropanethioate (Step 10.2). t_(R): 1.00min and 1.21 min (LC-MS 1); ESI-MS: 534/536 [M−H]⁺ (LC-MS 1); R_(f)=0.45(EtOAc/MeOH 9:1).

Step 10.4:5-(4-chlorophenyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxynicotinoyl)pyrrolidine-2,4-dione

The title compound was prepared in analogy to the procedure described inStep 1.3 using ethyl2-(4-chlorophenyl)-2-(N-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-3-oxopropanamido)acetate(Step 10.3). t_(R): 0.65 min (LC-MS 1); ESI-MS: 490/492 [M+H]⁺ (LC-MS1).

EXAMPLE 11(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% ee) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralCel OD-H 30×250 mm; mobile phase: scCO₂/EtOH 60:40(isocratic), flow: 50 mL/min) of the racemic mixture of6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 10).

(S)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.88 min (system: Thar analytical SFC; column: ChiralCel OD-34.6×150 mm; mobile phase: scCO₂/EtOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 3.54 min (system: Thar analytical SFC; column: ChiralCel OD-34.6×150 mm; mobile phase: scCO₂/EtOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

EXAMPLE 126-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxynicotinoyl)-pyrrolidine-2,4-dione(Step 10.4) and methyl hydrazine. t_(R): 0.92 min (LC-MS 1); ESI-MS:500/502 [M+H]⁺ (LC-MS 1); R_(f)=0.37 (CH₂Cl₂/MeOH 10:1); ¹H NMR (400MHz, DMSO-d₆) δ ppm 2.46 (s, 3H) 2.63 (s, 3H) 3.63 (s, 3H) 3.94 (m, 3H)6.73 (s, 1H) 7.14 (dd, J=7.4, 4.9 Hz, 1H) 7.34 (d, J=1.7 Hz, 1H)7.51-7.36 (m, 4H) 8.26 (dd, J=5.0, 1.9 Hz, 1H) 8.32 (dd, J=7.5, 1.9 Hz,1H) 8.42 (s, 1H).

EXAMPLE 13(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% ee) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO₂/isopropanol 50:50(isocratic), flow: 40 mL/min) of the racemic mixture of6-(4-chlorophenyl)-5-(3,8-dimethyl[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 12).

(S)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.90 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 50:50(isocratic), flow: 2 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 5.51 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/isopropanol (0.05% DEA) 50:50(isocratic), flow: 2 mL/min; detection UV: 220 nm).

EXAMPLE 14(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% ee) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO_(2/)MeOH 60:40(isocratic), flow: 50 mL/min) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 5).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.37 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 3.71 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

EXAMPLE 15(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxvethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% ee) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO_(2/)MeOH 60:40(isocratic), flow: 50 mL/min) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 4).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.18 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 3.74 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

EXAMPLE 166-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) and6-bromo-3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridine (Step16.5). t_(R): 0.98 min (LC-MS 1); ESI-MS: 451/453 [M+H]⁺ (LC-MS 1);R_(f)=0.42 (EtOAc/MeOH 9:1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 8.68 (s,1H), 7.50 (s, 1H), 7.42 (s, 4H), 6.66 (s, 1H), 6.03-5.85 (m, 2H), 3.47(s, 3H), 2.51 (s, 3H), 2.05-2.00 (m, 1H), 1.15-1.09 (m, 1H), 1.09-0.96(m, 3H).

Step 16.1: 2-hydrazinyl-3-methyl-5-nitropyridine

Hydrazine hydrate (12.7 mL, 0.26 mol) was added to a solution of2-chloro-3-methyl-5-nitropyridine (15 g, 87 mmol) in EtOH (150 mL). Thereaction mixture was stirred for 2 h at 60° C. Cooling in an ice bathled to crystalline product, which was filtered off and washed with H₂Oand Et₂O to provide the title compound (14.6 g, 95) as a yellow solid.t_(R): 0.42 min (LC-MS 1); ESI-MS: 169 [M+H]⁺ (LC-MS 1)

Step 16.2: 2-fluoroacetic acid anhydride

N,N′-Dicyclohexylcarbodiimide (14.5 g, 70.5 mmol) was added to asolution of 2-fluoroacetic acid (5 g, 64 mmol) in THF (64 mL). Thereaction mixture was stirred for 2 h at 25° C. The precipitate wasfiltered off and the filtrate was used directly for Step 16.3.

Step 16.3: 2-fluoro-N′-(3-methyl-5-nitropyridin-2-yl)acetohydrazide

2-Hydrazinyl-3-methyl-5-nitropyridine (5 g, 29.7 mmol) was added to asolution of 2-fluoroacetic anhydride in THF (65.4 mL, 32 mmol, Step16.2). The reaction mixture was stirred for 10 min and then partiallyconcentrated. Dilution of the residue with H₂O (250 mL) led toprecipitation of the product, which was filtered off and washed with H₂Oand a small amount of Et₂O. t_(R): 0.49 min (LC-MS 1); ESI-MS: 229[M+H]⁺ (LC-MS 1); contains 40% 1,3-dicyclohexylurea.

Step 16.4:3-(fluoromethyl)-8-methyl-6-nitro-[1,2,4]triazolo[4,3-a]pyridine

To a solution of2-fluoro-N′-(3-methyl-5-nitropyridin-2-yl)acetohydrazide (9.1 g, 23.9mmol, Step 16.3) in ACN (150 mL) was added DI PEA (3.13 mL, 18 mmol),followed by dropwise addition of POCl₃ (3.35 mL, 35.9 mmol). Thereaction mixture was stirred for 1 h at RT and 16 h at 70° C., cooled toRT and concentrated, then poured into a small amount of warm water andstirred for 30 min. After neutralization with NaHCO₃ to pH 4, theproduct was extracted with EtOAc/MeOH 9:1. The organic layers werewashed with brine, dried over MgSO₄, filtered and concentrated.Purification by silica gel column chromatography [hexane/(EtOAc/MeOH9:1) 90:10 to 0:100] gave the title product (4.32 g, 77%) as a yellowsolid. t_(R): 0.59 min (LC-MS 1); ESI-MS: 211 [M+H]⁺ (LC-MS 1).

Step 16.5:3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine

A mixture of3-(fluoromethyl)-8-methyl-6-nitro-[1,2,4]triazolo[4,3-a]pyridine (4.3 g,20.46 mmol) and Pd/C 10% (1.3 g) in MeOH (50 mL) was hydrogenated at 55°C. for 6 h. The catalyst was filtered off and the filtrate wasconcentrated. Purification by silica gel column chromatography[hexane/(EtOAc/MeOH 9:1) 50:50 to 0:100] gave the title compound (1.15g, 31%) as a bown oil. t_(R): 0.40 min (LC-MS 1); ESI-MS: 181 [M+H]⁺(LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.48 (s, 1H), 6.89 (s, 1H),5.86 (d, J=49 Hz, 2H), 5.26 (s, 2H), 2.49 (s, 3H).

EXAMPLE 17(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>97% ee) afterchiral preparative chromatography (system: Thar SFC200; column:Chiralpak AD-H 50×250 mm; mobile phase: scCO₂/MeOH 60:40 (isocratic),flow: 150 g/min) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 16).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,Rt: 1.70 min (system: Thar/Waters SFC Investigator MS; column: ChiralpakAD-H 4.6×250 mm; mobile phase: scCO₂/EtOH 65:35 (isocratic), flow: 4mL/min; detection UV: 254 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,Rt: 3.52 min (system: Thar/Waters SFC Investigator MS; column: ChiralpakAD-H 4.6×250 mm; mobile phase: scCO₂/EtOH 65:35 (isocratic), flow: 4mL/min; detection UV: 254 nm).

EXAMPLE 186-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 4.3) and3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine (Step16.5). t_(R): 0.99 min (LC-MS 1); ESI-MS: 495/497 [M+H]⁺ (LC-MS 1), 1HNMR (400 MHz, DMSO-d6) δ ppm 0.92-1.21 (m, 4H) 1.94-2.10 (m, 1H) 2.51(s, 3H) 3.12 (s, 3H) 3.45 (t, J=5.3 Hz, 2H) 3.64-3.79 (m, 1H) 3.87-4.03(m, 1H) 5.92 (dq, J=49.3, 12.0 Hz, 2H) 6.58 (s, 1H) 7.35-7.44 (m, 4H)7.52 (s, 1H) 8.69 (s, 1H).

EXAMPLE 19(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihvdropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]-pyrazol-4(1H)-one(Step 19.1) and 6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine toprovide after separation by SFC (propyl-pyridyl-urea (250×30 mm, 5 μm),20-25% B in 6 min, A: scCO₂, B: MeOH; flow: 100 mL/min) the (2R,6R)- and(2R,6S)-diastereoisomers.

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(peak 1). t_(R): 1.00 min (LC-MS 1); ESI-MS: 531/533 [M+H]⁺ (LC-MS 1),1H NMR (400 MHz, DMSO-d₆) δ ppm 0.99-1.11 (m, 3H) 1.15-1.22 (m, 1H) 2.05(s, 1H) 2.44 (s, 3H) 2.63 (s, 3H) 3.41-3.51 (m, 1H) 4.15-4.31 (m, 2H)6.60 (s, 1H) 7.01 (d, J=6.5 Hz, 1H) 7.37 (s, 1H) 7.42 (s, 4H) 8.42 (s,1H)

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(peak 2). t_(R): 0.94 min (LC-MS 1); ESI-MS: 495/497 [M+H]⁺ (LC-MS 1),1H NMR (400 MHz, DMSO-d₆) δ ppm 0.97-1.19 (m, 4H) 1.97-2.09 (m, 1H) 2.44(s, 3H) 2.63 (s, 3H) 3.73-3.81 (m, 1H) 3.94-4.04 (m, 1H) 4.32-4.45 (m,1H) 6.61 (s, 1H) 6.68 (d, J=6.9 Hz, 1H) 7.30 (s, 1H) 7.39 (s, 4H) 8.38(s, 1H).

Step 19.1:6-(4-chlorophenyl)-3-cyclopropyl-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione (Step4.2) and (R)-1,1,1-trifluoro-3-hydrazinylpropan-2-ol. t_(R): 0.92 minand 0.98 min (LC-MS 1); ESI-MS: 386/388 [M+H]⁺ (LC-MS 1).

EXAMPLE 20(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]-pyrazol-4(1H)-one(Step 20.1) and 6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine toprovide after separation by SFC (propyl-pyridyl-urea (250×30 mm, 5 μm),20-25% B in 6 min, A: scCO₂, B: MeOH; flow: 100 mL/min) the (2R,6R)- and(2R,6S)-diastereoisomers.

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(peak 1). t_(R): 1.00 min (LC-MS 1); ESI-MS: 531/533 [M+H]⁺ (LC-MS 1),1H NMR (400 MHz, DMSO-d₆) δ ppm 0.99-1.21 (m, 4H) 1.95-2.06 (m, 1H) 2.44(s, 3H) 2.57 (s, 3H) 3.68 (dd, J=14.1, 9.8 Hz, 1H) 4.24 (d, J=13.8 Hz,1H) 4.53 (br. s., 1H) 6.18 (s, 1H) 6.86 (s, 1H) 7.28-7.32 (m, 2H)7.33-7.40 (m, 2H) 7.62 (br. s., 1H) 8.36 (s, 1H).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(peak 2). t_(R): 0.94 min (LC-MS 1); ESI-MS: 495/497 [M+H]⁺ (LC-MS 1),1H NMR (400 MHz, DMSO-d₆) δ ppm 1.03-1.19 (m, 3H) 1.23-1.31 (m, 1H) 2.08(s, 1H) 2.57 (s, 3H) 2.65 (s, 3H) 4.03 (d, J=5.0 Hz, 2H) 4.38-4.50 (m,1H) 5.16-5.26 (m, 1H) 5.99 (s, 1H) 6.93 (s, 1H) 7.22 (d, J=8.4 Hz, 2H)7.37 (d, J=8.4 Hz, 2H) 8.04 (s, 1H).

Step 20.1:6-(4-chlorophenyl)-3-cyclopropyl-1-((R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione (Step4.2) and (S)-1,1,1-trifluoro-3-hydrazinylpropan-2-ol. t_(R): 0.92 minand 0.97 min (LC-MS 1); ESI-MS: 386/388 [M+H]⁺ (LC-MS 1).

EXAMPLE 216-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 21.1) and 6-bromo-1,4-dimethyl-1H-benzo[d][1,2,3]-triazole (Step8.3). t_(R): 1.10 min (LC-MS 1); ESI-MS: 499/501 [M+H]⁺ (LC-MS 1), 1HNMR (400 MHz, DMSO-d₆) δ ppm 1.33-1.05 (m, 4H) 2.21-2.09 (m, 1H) 2.60(s, 3H) 3.32 (s, 3H) 4.21 (s, 3H) 6.14 (d, J=2.0 Hz, 1H) 6.83 (s, 1H)7.33-7.16 (m, 4H) 7.41 (s, 1H) 7.48 (d, J=2.0 Hz, 1H) 7.77 (s, 1H).

Step 21.1:6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)pyrrolidine-2,4-dione (Step4.2) and 5-hydrazinyl-1-methyl-1H-pyrazole. t_(R): 0.89 min (LC-MS 1);ESI-MS: 354/356 [M+H]⁺ (LC-MS 1), 1H NMR (400 MHz, DMSO-d₆) δ ppm0.87-1.30 (m, 4H) 1.95-2.22 (m, 1H) 3.46 (s, 3H) 5.70 (s, 1H) 6.21 (d,J=2.1 Hz, 1H) 7.10 (d, J=8.4 Hz, 2H) 7.35 (d, J=8.4 Hz, 2H) 7.41 (d,J=2.1 Hz, 1H) 8.57 (s, 1H).

EXAMPLE 226-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo-[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 1 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)-1-(3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)pyrrolidine-2,4-dione(Step 22.8) and methyl hydrazine. t_(R): 1.03 min (LC-MS 1); R₁=0.38(EtOAc/MeOH 9:1); ESI-MS: 485/487 [M+H]⁺ (LC-MS 1), 1H NMR (400 MHz,DMSO-d₆) δ ppm 1.17-0.95 (m, 4H) 2.07-1.99 (m, 1H) 3.47 (s, 3H) 3.98 (s,3H) 6.76 (s, 1H) 7.14 (s, 1H) 7.50-7.39 (m, 4H) 7.69 (t, J=51.4 Hz, 1H)8.41 (s, 1H).

Step 22.1: 2,2-difluoro-N′-(3-methoxy-5-nitropyridin-2-yl)acetohydrazide

To a suspension of 2-hydrazinyl-3-methoxy-5-nitropyridine (2.5 g, 13.3mmol in dioxane (25 mL) was added dropwise 2,2-difluoroacetic anhydride(1.75 mL, 14.0 mmol) at RT. After stirring the reaction mixture for 0.5h at RT, the suspension was added to ice-water (100 mL). Theprecipitated product was filtered off, washed with water and dried at50° C. under reduced pressure for 20 h to provide the title product(3.45 g, 97%) as a yellow solid. t_(R): 0.56 min (LC-MS 1); R_(f)=0.34(CH₂Cl₂/MeOH 10:1); ESI-MS: 263 [M+H]⁺ (LC-MS 1), 1H NMR (400 MHz,DMSO-d₆) δ ppm 3.99 (s, 3 H), 6.45 (t, J=52.8 Hz, 1H), 7.79 (d, J=2.2Hz, 1H), 8.65 (d, J=2.2 Hz, 1H), 9.64 (s, 1H), 11.02 (s, 1H).

Step 22.2:3-(difluoromethyl)-8-methoxy-6-nitro-[1,2,4]triazolo[4,3-a]pyridine

To a suspension of2,2-difluoro-N′-(3-methoxy-5-nitropyridin-2-yl)acetohydrazide (3.45 g,13.16 mmol) and DIPEA (1.72 mL, 9.9 mmol) in ACN (20 mL) was added underAr slowly POCl₃(1.85 mL, 19.75 mmol). The reaction mixture was heatedfor 15 h at 90° C. The reaction mixture was slowly added to H₂O at 40°C. and after careful neutralization with NaHCO₃ to pH 6.5 extracted withCH₂Cl₂. Combined extracts were washed with a small amount of brine,dried over MgSO₄, filtered and concentrated. Purification by silica gelcolumn chromatography [hexane/(CH₂Cl₂/MeOH 9:1) 75:25 to 0:100] gave thetitle product (2.29 g, 69%) as a yellow solid. t_(R): 0.64 min (LC-MS1); ESI-MS: 245 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 4.16(s, 3H) 7.50 (s, 1H) 7.89 (t, J=51.5 Hz, 1H) 9.38 (s, 1H).

Step 22.3:3-(difluoromethvI)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-amine

A solution of3-(difluoromethyl)-8-methoxy-6-nitro-[1,2,4]triazolo[4,3-a]pyridine (2.2g, 8.3 mmol) in MeOH (75 mL) was hydrogenated over 10% Pd/C (0.86 g) for4 h at 50° C. and 1000 mbar H₂. The reaction mixture was filtered overCelite and the filtrate was concentrated. The solidified crude productwas triturated in CH₂Cl₂/MeOH 9:1, the solid filtered off, washed withCH₂Cl₂ and dried to give the title product (1.44 g, 75% yield) as abeige solid. t_(R): 0.44 min (LC-MS 1); ESI-MS: 215 [M+H]⁺ (LC-MS 1); ¹HNMR (400 MHz, DMSO-d₆) δ ppm 3.96 (s, 3H) 5.43 (s, 2H) 6.56 (s, 1H) 7.35(s, 1H) 7.61 (t, J=51.5 Hz, 1H).

Step 22.4:6-azido-3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

To a suspension of3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-amine (1.42g, 6.63 mmol) in ACN (10 mL) was added at 0° C. trimethylsilyl azide(2.65 mL, 19.9 mmol. After 10 min stirring at 0-5° C. a solution oftert-butylnitrite (4.73 mL, 39.8 mmol) in ACN (20 mL) over a period of30 min. The reaction mixture was stirred for 20 h at RT, concentrated,and the crude product was purified by silica gel column chromatography[hexane/(CH₂Cl₂/MeOH 9:1) 50:50 to 0:100] to provide the title product(2.29 g, 69%) as a yellow solid. t_(R): 0.70 min (LC-MS 1); ESI-MS: 241[M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 4.07 (s, 3H) 6.83 (s,1H) 7.73 (t, J=51.6 Hz, 1H) 8.15 (s, 1H).

Step 22.5: (E)-ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)imino)acetate

To a solution of6-azido-3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (500mg, 2.082 mmol) and ethyl 2-(4-chlorophenyl)-2-oxoacetate (465 mg, 2.186mmol) in THF (12 mL) was added in portions triphenylphosphine (655 mg,2.498 mmol). The reaction mixture was stirred for 1 h at rt, 24 h at 70°C. and 12 h at 90° C. The reaction mixture was added to sat. NaHCO₃solution and the product was extracted with EtOAc. Combined extractswere washed with brine, dried over MgSO₄, filtered and concentrated toprovide after silica gel column chromatography (hexane/EtOAc 75:25 to0:100) the title product (518 mg, 58%) as a yellow solid. R_(f)=0.55(EtOAc); t_(R): 1.13 min (LC-MS 1); ESI-MS: 409/411 [M+H]⁺ (LC-MS 1); ¹HNMR (400 MHz, DMSO-d₆) δ ppm 0.98 (t, J=7.1 Hz, 3H), 4.05 (s, 3H), 4.24(q, J=7.1 Hz, 2H), 6.85 (s, 1H), 7.69 (d, J=8.4 Hz, 2H), 7.73 (t, J=51.0Hz, 1H), 7.74 (s, 1H), 7.92 (d, J=8.4 Hz, 2H).

Step 22.6: ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)acetate

To a solution of (E)-ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)imino)acetate(510 mg, 1.25 mmol) in toluene (8 mL), isopropanol (4.6 mL) and H₂O (0.1mL) was added under argon [Ru(CO)₂(Ph₄C₄CO)]₂(28 mg, 0.025 mmol, Can. J.Chem, 2005, 83, 909)) and the reaction mixture was heated at 110° C. for45 min in the microwave. The reaction mixture was concentrated and thecrude product was purified by silica gel column chromatography(hexane/EtOAc 75:25 to 0:100) the give title product (461 mg, 88%) as alight yellow solid. R_(f)=0.35 (EtOAc); t_(R): 1.07 min (LC-MS 1);ESI-MS: 411/413 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₅) δ ppm 1.16(t, J=7.1 Hz, 3H), 3.96 (s, 3H), 3.99-4.26 (m, 2H), 5.34 (d, J=7.9 Hz,1H), 6.83 (d, J=8.0 Hz, 1H), 6.89 (s, 1H), 7.13 (s, 1H), 7.49 (d, J=8.4Hz, 2H), 7.56 (d, J=8.4 Hz, 2H) 7.57 (t, J=52.4 Hz, 1H).

Step 22.7: ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)acetate

The title compound was prepared in analogy to the procedure described inStep 1.2 using ethyl2-(4-chlorophenyl)-2-((3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)amino)-acetate(Step 21.6) and S-tert-butyl 3-cyclopropyl-3-oxopropanethioate (Step1.5). t_(R): 1.04 min (LC-MS 1); ESI-MS: 521/523 [M−H]⁺ (LC-MS 1);R_(f)=0.34 (EtOAc).

Step 22.8:5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)-1-(3-(difluoromethyl)-8-methoxy-[1,2,4]-triazolo[4,3-a]pyridin-6-yl)pyrrolidine-2,4-dione

The title compound was prepared in analogy to the procedure described inStep 1.3 using5-(4-chlorophenyl)-3-(cyclopropanecarbonyl)-1-(3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]-pyridin-6-yl)pyrrolidine-2,4-dione(Step 21.7). R_(f)=0.13 (CH₂Cl₂/MeOH 10:1); t_(R): 0.88 min (LC-MS 1);ESI-MS: 475/477 [M−H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm1.06-1.19 (m, 4H), 3.13-3.21 (m, 1H), 3.93 (s, 3H), 5.87 (s, 1H), 7.16(s, 1H), 7.65 (t, J=51.0 Hz, 1H), 8.63 (s, 1H).

Example 236-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 6 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) and 6-chloro-3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazine(CAS Reg. 23069-72-9). R_(f)=0.24 (EtOAc/MeOH 9:1); t_(R): 1.06 min(LC-MS 1); ESI-MS: 434/436 [M−H]⁺ (LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δppm 0.98-1.16 (m, 4H), 1.99-2.09 (m, 1H), 2.55 (s, 3H), 2.57 (s, 3H),3.46 (s, 3H), 6.71 (s, 1H), 7.40-7.54 (m, 4H), 8.16 (s, 1H).

EXAMPLE 24(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was obtained enantiomerically pure (>99% ee) afterchiral preparative chromatography (system: Mg II preparative SFC;column: ChiralPak AD-H 30×250 mm; mobile phase: scCO_(2/)MeOH 60:40(isocratic), flow: 50 mL/min) of the racemic mixture of6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-di-hydropyrrolo[3,4-c]pyrazol-4(1H)-one(Example 22).

(S)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 2.75 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/nin; detection UV: 220 nm).

(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one,t_(R): 5.06 min (system: Thar analytical SFC; column: ChiralPak AD-H4.6×250 mm; mobile phase: scCO₂/MeOH (0.05% DEA) 60:40 (isocratic),flow: 2.4 mL/min; detection UV: 220 nm).

EXAMPLE 256-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 6 using6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 21.1) and 6-chloro-3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazine(CAS Reg. 23069-72-9). t_(R): 1.07 min (LC-MS 1); ESI-MS: 500/502 [M+H]⁺(LC-MS 1), 1H NMR (400 MHz, DMSO-d₆) δ ppm 1.09-1.32 (m, 4H), 2.17 (tt,J=8.4, 5.1 Hz, 1H), 2.52 (s, 3H), 2.58 (s, 3H), 3.47 (s, 3H), 6.13 (d,J=2.0 Hz, 1H), 6.76 (s, 1H), 7.32 (s, 4H), 7.44 (d, J=2.0 Hz, 1H), 8.15(d, J=1.5 Hz, 1H).

EXAMPLE 266-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(1-methyl-1H-pvrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

The title compound was prepared in analogy to the procedure described inExample 4 using6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 21.1) and 6-bromo-3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridine.t_(R): 0.93 min (LC-MS 1); ESI-MS: 499/501 [M+H]⁺ (LC-MS 1), 1H NMR (400MHz, DMSO-d₆) δ ppm 1.03-1.30 (m, 4H) 2.14 (d, J=4.7 Hz, 1H) 2.45 (s,3H) 2.62 (s, 3H) 3.48 (s, 3H) 6.10 (s, 1H) 6.71 (s, 1H) 7.23 (d, J=8.4Hz, 2H) 7.31 (d, J=8.1 Hz, 2H) 7.34 (br. s., 1H) 7.47 (s, 1H) 8.37 (s,1H).

EXAMPLE 27 tert-butyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate

The title compound was prepared in analogy to the procedure described inExample 6 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1) and tert-butyl(6-bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate (Step27.3). t_(R): 1.15 min (LC-MS 1); ESI-MS: 534/536 [M+H]⁺ (LC-MS 1), 1HNMR (400 MHz, DMSO-d₆) δ ppm 0.95-1.05 (m, 4H) 1.49 (s, 9H) 2.02 (m, 1H)2.62 (s, 3H) 3.46 (s, 3H) 6.58 (s, 1H) 7.40 (m, 4H) 7.78 (s, 1H) 8.21(s,1H) 9.18 (s, 1H).

Step 27.1: N′-(3,5-dibromopyridin-2-yl)acetohydrazide

The title compound was prepared in analogy to the procedure described inExample 5 (Step 5.2) using 3,5-dibromo-2-hydrazinylpyridine (CAS reg.1289024-95-8) and acetic acid anhydride. t_(R): 0.65 min (LC-MS 1);ESI-MS: 308/310/312 [M+H]⁺ (LC-MS 1), 1H NMR (400 MHz, DMSO-d₆) δ ppm1.89 (s, 3H), 8.12 (d, J=2.1 Hz, 1H), 8.18 (d, J=2.1 Hz, 1H), 8.36 (s,1H), 9.78 (s, 1H).

Step 27.2: 6,8-dibromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridine

To a suspension of N′-(3,5-dibromopyridin-2-yl)acetohydrazide (1.5 g,4.86 mmol) in dioxane (15 mL) was added acetic acid (6.95 mL, 121 mmol)and the reaction mixture was heated in a sealed tube at 120° C. for 48h. The reaction mixture was concentrated and the crude product waspurified by silica gel column chromatography [hexane/(CH₂Cl₂/MeOH 9:1)50:50 to 0:100] to provide the title product (1.26 g, 88%) as acolorless solid. t_(R): 0.63 min (LC-MS 1); ESI-MS: 290 (292/294 [M+H]⁺(LC-MS 1); ¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.69 (s, 3H), 7.94 (d, J=1.4Hz, 1H), 8.83 (d, J=1.4 Hz, 1H).

Step 27.3: tert-butyl(6-bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate

To a suspension of 6,8-dibromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridine(1.0 g, 3.40 mmol, Step 27.2), tert-butyl carbamate (0.598 g, 5.10 mmol)and Cs₂CO₃ (2.217 g, 6.81 mmol) in dioxane (15 mL) was added under ArXantphos (0.295 g, 0.510 mmol) and Pd₂(dba)₃CHCl₃ (0.176 g, 0.170 mmol)and the reaction mixture was heated for 8 h at 100° C. The reactionmixture was added to brine and the product was extracted with EtOAc/THF5:1. Combined extracts were washed with brine, dried over MgSO₄,filtered and concentrated. The crude product was purified by silica gelcolumn chromatography [hexane/(CH₂Cl₂/MeOH 9:1) 80:20 to 0:100] toprovide the title product (0.6 g, 53%) as a colorless solid. t_(R): 0.97min (LC-MS 1); ESI-MS: 327/329 [M+H]⁺ (LC-MS 1); ¹H NMR (400 MHz,DMSO-d₆) δ ppm 1.50 (s, 9H), 2.67 (s, 3H), 7.72 (d, J=1.5 Hz, 1H), 8.42(d, J=1.5 Hz, 1H), 9.46 (s, 1H).

EXAMPLE 285-(8-amino-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one

To a solution of tert-butyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]-pyrazol-5(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate((59 mg, 0.108 mmol, Example 27) in CH₂Cl₂ (2 mL) was added TFA (0.334mL, 4.33 mmol) and the reaction mixture was stirred for 3.5 h at RT. Thereaction mixture was added to sat. NaHCO₃ solution and the product wasextracted with EtOAc. Combined extracts were washed with brine, driedover MgSO₄, filtered and concentrated. The crude product was purified bysilica gel column chromatography [hexane/(CH₂Cl₂/MeOH 9:1) 80:20 to0:100] to provide the title product (24 mg, 49%) as a light yellowsolid. t_(R): 0.87 min (LC-MS 1); ESI-MS: 434/436 [M+H]⁺ (LC-MS 1); ¹HNMR (400 MHz, DMSO-d₆) δ ppm 0.95-1.15 (m, 4H) 2.00 (m, 1H) 2.56 (s, 3H)3.46 (s, 3H) 6.06 (s, 1H) 6.34 (d, J=1.6 Hz, 1H) 6.47 (s, 1H) 7.32-7.46(m, 4H) 7.75 (s, 1H).

EXAMPLE 29 ethyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5-(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate

The title compound was prepared in analogy to the procedure described inExample 6 using6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one(Step 5.1), ethyl(6-bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate (Step29.1) and K₃PO₄as base. t_(R): 0.97 min (LC-MS 1); ESI-MS: 506/508[M+H]⁺ (LC-MS 1), 1H NMR (400 MHz, DMSO-d₆) δ ppm 0.96-1.16 (m, 4H),1.26 (t, J=7.1 Hz, 3H), 1.97-2.05 (m, 1H), 2.64 (s, 3H), 3.48 (s, 3H),4.18 (q, J=7.1 Hz, 2H), 6.60 (s, 1H), 7.37-7.44 (m, 4H), 7.82 (s, 1H),8.27 (d, J=1.8 Hz, 1H), 9.74 (s, 1H).

Assays

The activity of a compound according to the present invention can beassessed by the following methods.

TR-FRET In-Vitro Binding Assays for BRD2, BRD3, and BRD4:

All assays were performed in 384 well microtiter plates. Each assayplate contained 8-point serial dilutions for 40 test compounds, plus 16high- and 16 low controls. Liquid handling and incubation steps weredone on an Innovadyne Nanodrop Express equipped with a robotic arm(Thermo CatX, Perkin Elmer/Caliper Twister II) and an incubator (LiconicSTX40, Thermo Cytomat 2C450). The assay plates were prepared by additionof 50 nl per well of compound solution in 90% DMSO HummingBirdnanodispenser (Zinsser Analytic). The assay was started by stepwiseaddition of 4.5 μl per well of bromo domain protein (50 mM HEPES, pH7.5, 0.005% Tween20, 0.1% BSA, 50 mM NaCl, 45 nM His-Brd2(60-472) or 45nM His-Brd3(20-477) or 45 nM His-Brd4(44-477) all proteins producedin-house) and 4.5 μl per well of peptide solution (50 mM HEPES, pH 7.5,0.005% Tween20, 0.1% BSA, 50 mM NaCl, 60 nM acetyl-histone H4 (AcK 5, 8,12, 16) (Biosyntan GmbH)). Reactions were incubated at 30° C. for 35minutes. Subsequently 4.5 μl per well detection mix (50 mM HEPES, pH7.5, 0.005% Tween20, 0.1% BSA, 50 mM NaCl, 3 nM Eu-labeled anti-His6antibody, 21 nM streptavidin-allophycocyanin) were added. After 35minutes incubation at 30° C., plates were measured in a Perkin ElmerEnVision multilabel reader. Concentrations causing 50% inhibition (IC50values) were determined from percent inhibition values at differentcompound concentrations by non-linear regression analysis.

AlphaScreen In-Vitro Binding Assay for CREBBP

In order to assess bromodomain selectivity, we set up a binding assayusing the bromodomain encoded by the CREBBP gene. Compounds were testedin the CREBBP assay with a similar protocol, however using AlphaScreen(Amplified Luminescent Proximity Homogeneous Assay, Perkin Elmer) asdetection readout instead of TR-FRET. The assay was started by stepwiseaddition of 4.5 μl per well of bromo domain protein (50 mM HEPES, pH7.5, 0.005% Tween20, 0.02% BSA, 150 mM NaCl, 324 nMHis-CREBBP(1081-1197) (custom production at Viva Biotech Ltd.)) and 4.5μl per well of peptide solution (50 mM HEPES, pH 7.5, 0.005% Tween20,0.02% BSA, 150 mM NaCl, 120 nM acetyl-histone H4 (AcK 5, 8, 12)(Biosyntan GmbH)). Reactions were incubated at 30° C. for 35 minutes.Subsequently 4.5 μl per well detection mix (50 mM HEPES, pH 7.5, 0.005%Tween20, 0.02% BSA, 150 mM NaCl, 45 μg/ml Ni-chelate acceptor beads, 45μg/ml streptavidin-donor beads) (Perkin Elmer)) were added. After 60minutes incubation at room temperature, plates were measured in a PerkinElmer EnVision multilabel reader. IC50 values were determined frompercent inhibition values at different compound concentrations bynon-linear regression analysis.

For further bromodomain selectivity profiling, additional panel assayswere performed using analog protocols with minor modifications specificfor the individual assay, using either TR-FRET or AlphaScreen fordetection.

Preparation of Compound Dilutions

Test compounds were dissolved in DMSO (10 mM) and transferred into 1.4mL flat bottom or V-shaped Matrix tubes carrying a unique 2D matrix. Thestock solutions were stored at +2° C. if not used immediately. For thetest procedure the vials were defrosted and identified by a scannerwhereby a working sheet was generated that guided the subsequent workingsteps. Compound dilutions were made in 96 well plates. This formatenabled the assay of maximally 40 individual test compounds at 8concentrations (single points) including 4 reference compounds, ifdesired (known BET inhibitors from the prior art, for this and otherassays of the type disclosed herein). The dilution protocol included theproduction of “pre-dilution plates”, “master plates” and “assay plates”.

Pre-dilution plates: 96 polypropylene well plates were used aspre-dilution plates. A total of 4 pre-dilution plates were preparedincluding 10 test compounds each on the plate positions A1-A10, onestandard compound at A11 and one DMSO control at A12. All dilution stepswere done on a HamiltonSTAR robot.

Master plates: 30 μL of individual compound dilutions including standardcompound and controls of the 4 “pre-dilution plates” were transferredinto a 384 “master plate” including the following concentrations 10000,3003, 1000, 300, 100, 30, 10 and 3 μM, respectively in 90% of DMSO.

Assay plates: Identical “assay plates” were then prepared by pipetting50 nL each of compound dilutions of the “master plates” into 384-well“assay plates” by means of a HummingBird 384-channel dispenser. Theseplates were used directly for the assay which was performed in a totalvolume of 13.55 μL. This led to a final compound concentration of 37,11, 3.7, 1.1, 0.37, 0.11, 0.037 and 0.011 μM and a final DMSOconcentration of 0.37% in the assay.

Cell Growth Inhibition Assay

The human leukemia cell lines MV-4-11, THP-1 and K-562 were employed tocharacterize the effect of BET inhibitors on cellular proliferation andviability. Cells were obtained from the American Type Culture Collection(ATCC) and cultured at 37° C. in a humidified 5% CO₂ incubator in thefollowing media: MV-4-11: DMEM high glucose (Animed #1-26F01-1), 10% FCS(Animed #2-01F26-I), 4 mM L-Glutamine (Animed #5-10K50), 1 mM SodiumPyruvate (Animed #G03625P), lx Penicillin-Streptomycin (Animed#F12478P); K-562: Iscove's MEM (Animed #1-28F16-I), 10% FCS (Animed#2-01F26-I), 4 mM L-Glutamine (Animed #5-10K50), 1×Penicillin-Streptomycin (Animed #F12478P); THP-1: RPMI-1640 (Animed#1-41F01-I), 10% FCS (Animed #2-01F26-I), 2 mM L-Glutamine (Animed#5-10K50), 10 mM HEPES (Animed #5-31F100), 1 mM Sodium Pyruvate (Animed#G03625P), 1× Penicillin-Streptomycin (Animed #F12478P). The AML linesMV-4-11 and THP-1 are very sensitive to BET inhibitors and show massivecell death upon BET inhibition (Zuber et al., Nature, 478 (2011),524-8). Compound-mediated suppression of cell proliferation/viabilitywas assessed by quantification of cellular ATP levels using theCellTiter-Glo (CTG) reagent (Promega). Briefly, cells were seeded in 20μl fresh medium into 384-well plates, followed by addition of 5 μlmedium containing compound dilutions at 5-fold their final intendedconcentration. Dose-response effects were assessed by 3-fold serialdilutions of the test compound, starting at 10 μM. Following incubationof the cells for 4 days at 37° C. and 5% CO₂, the effect of inhibitorson cell viability was quantified following addition of 20 μl CTG andluminescence quantification (integration time: 100 ms) as per vendormanual, using a correspondingly equipped Tecan M200 multi-modeplatereader (TECAN, Switzerland). For data analysis, the assaybackground value determined in wells containing medium, but no cells,was subtracted from all data points. To enable differentiation ofcytotoxic from cytostatic compounds, the number of viable cells isassessed relative to that observed at the time of compound additionusing a separate cell plate (day 0). The effect of a particular testcompound concentration on cell proliferation/viability is expressed aspercentage of the background- and day 0-corrected luminescence readingobtained for cells treated with vehicle only (DMSO, 0.1% finalconcentration), which is set as 100%, whereas that luminescence readingfor wells containing medium is set as −100%. Compound concentrationsleading to half-maximal (IC50) and total growth inhibition (TGI) weredetermined using standard four parameter curve fitting.

Nut-Foci Formation Assay

HCC2494 NUT midline carcinoma cells (expressing BRD4-NUT-fusion) wereobtained from the University of Texas Southwestern and cultured inRPMI-1640 medium containing 10% Foetal Calf Serum at 37° C. in ahumidified 5% CO₂ incubator.

Compound-mediated inhibition of BRD4 activity was monitored byquantification of the number and intensity of nuclear BRD4-NUT fociusing automated immunofluorescence microscopy. Briefly, 5000 cells in 20μl fresh medium were seeded into Poly-D-Lysine-precoated 384-well platesand incubated overnight at 37° C. and 5% CO₂, followed by addition of 5μl medium containing compound dilutions at 5-fold their final intendedconcentration. Dose-response effects were assessed by 3-fold serialdilutions of the test compound, starting at 10 μM. Following incubationof the cells for 24 hours at 37° C. and 5% CO₂, the cells were fixed byincubation with 3.7% formaldehyde for 10 min, followed byimmunofluorescence staining using rabbit anti-NUT (Cell SignalingTechnologies, Cat#3625) as primary, and AlexaFluor488-labeled goatanti-rabbit (Invitrogen, Cat#A11008) as secondary antibody (lattercomplemented with 1 μg/mL Hoechst33342 as DNA dye). Assay plates wereimaged using the appropriate filter sets on the Cellomics VTi automatedfluorescence microscopy platform (ThermoFisher Scientific) and thepopulation average of the number of NUT-foci per nucleus is quantifiedusing the Cellomics Spot Detection BioApplication image analysisalgorithm (ThermoFisher Scientific). The effect of a particular testcompound concentration on NUT-foci number and intensity is expressed aspercentage of the value obtained for cells treated with vehicle only(DMSO, 0.1% final concentration), which was set as 100. Compoundconcentrations leading to half-maximal (IC50) inhibition of theaforementioned readout parameters were determined using standard fourparameter curve fitting.

Using the biochemical and cellular assays as described in thisapplication compounds of the invention exhibit inhibitory efficacy inaccordance to Tables 1 and 2, provided infra.

TABLE 1 Biochemical IC50 values IC50 (μM) Example BRD4 BRD2 BRD3 CREBBP1 0.024 0.029 0.031 11.4 2 <0.011 0.011 0.012 6 3 <0.011 0.013<0.011 >37 4 <0.011 0.017 <0.011 7.3 5 0.028 0.054 0.044 >37 6 0.0220.038 0.025 21.6 7 <0.011 0.013 0.012 >37 8 0.018 0.028 0.02 4.8 9 0.0140.021 0.014 3.2 10 0.03 0.048 0.045 >37 11 0.042 0.046 0.037 >37 120.032 0.042 0.031 12.2 13 0.024 0.034 0.022 5.4 14 0.03 0.057 0.055 27.515 0.018 0.02 0.016 6.1 16 0.015 0.016 0.013 >37 17 <0.011 0.011 <0.0119.8 18 0.025 0.033 0.024 >37 19 0.023 0.029 0.025 9.4 20 0.015 0.0130.012 7.9 21 0.017 0.031 0.023 6.6 22 0.13 0.21 0.23 >37 23 24 <0.011<0.011 <0.011 19.2 25 0.025 0.032 0.024 >37 26 27 0.036 0.047 0.065 8.128 0.021 0.041 0.034 3.7 29 0.023 0.023 0.022

TABLE 2 Cellular IC50 values* HCS Brd4- THP-1 THP-1 K-562 K-562 NUTMV-4-11 MV-4-11 GI50 TGI GI50 TGI IC50 Example GI50 (μM) TGI (μM) (μM)(μM) (μM) (μM) (μM) 1 0.00542 0.0107 0.0096 0.0204 0.0519 >10 0.0162 20.00431 0.011215 0.00637 0.01495 0.0292 >10 0.004715 3 0.00949 0.023450.01245 0.02945 0.0735 >10 0.008265 4 0.009355 0.0208 0.0119 0.027950.0568 >10 0.009035 5 0.06495 0.104 0.08145 0.1475 0.373 >10 0.036 60.04455 0.09025 0.06305 0.1181 0.2035 >10 0.05475 7 0.002445 0.0062750.00565 0.0148 0.0463 >10 0.00214 8 0.00471 0.00953 0.007295 0.01760.02475 >10 9 0.00257 0.005745 0.00441 0.01076 0.014345 >10 10 0.034550.0643 0.0604 0.13685 0.13545 >10 11 0.00955 0.0174 0.02825 0.04280.09835 >10 12 0.0175 0.0378 0.04045 0.09735 0.10565 >10 13 0.014250.0298 0.02845 0.06465 0.0965 >10 14 0.0201 0.03955 0.0514 0.11850.1525 >10 15 0.00241 0.00579 0.00642 0.0139 0.0265 >10 16 0.006070.0113 0.0187 0.0516 0.122 >10 0.0121 17 0.00428 0.009765 0.0096850.0247 0.0631 >10 18 0.00673 0.01325 0.0192 0.04645 0.139 >10 0.00365 190.00523 0.0113 0.0147 0.0366 0.0584 >10 20 0.00647 0.0161 0.0209 0.04470.096 >10 21 0.01355 0.02725 0.0223 0.04445 0.0788 >10 22 0.2665 0.5740.814 1.33 1.18 >10 23 24 0.0006435 0.00157 0.001875 0.004910.010405 >10 25 0.00665 0.0159 0.0201 0.0444 0.0916 >10 26 27 0.0110750.0226 0.0228 0.04465 0.164 >10 0.0224 28 0.001565 0.003515 0.002830.00904 0.009655 >10 29 0.00113 0.00197 0.00259 0.00762 0.0236 >100.0022 *Values from either single determination or n ≧ 2 independentdeterminations

1. A compound of formula (I) or a pharmaceutically acceptable saltthereof,

wherein A is selected from

B is

C is

R¹ is methyl, optionally substituted with one or two fluoro; R² isselected from chloro and fluoro; R³ is selected from (C₁-C₄)alkyl andcyclopropyl; and R⁴ is selected from (C₁-C₄)alkyl, optionallysubstituted by —OH or —O—(C₁-C₄)alkyl; halo(C₁-C₄)alkyl substituted by—OH; or

or R³ is

and R⁴ is selected from H; (C₁-C₄)alkyl optionally substituted by —OH or—O—(C₁-C₄)alkyl; and cyclopropyl; R⁵ is H; R⁶ is selected from methyl,methoxy, —NH₂ and —NH—C(O)—(C₁-C₄)alkyl R⁷ is methoxy; and * indicatesthe point of attachment to the remainder of the molecule.
 2. A compoundof formula (I), or a pharmaceutically acceptable salt thereof, accordingto claim 1, wherein R¹ is selected from methyl and difluoromethyl.
 3. Acompound of formula (I), or a pharmaceutically acceptable salt thereof,according to claim 1, wherein A is selected from


4. A compound of formula (I), or a pharmaceutically acceptable saltthereof, according to claim 1, wherein R³ is selected from methyl, ethyland cyclopropyl.
 5. A compound of formula (I), or a pharmaceuticallyacceptable salt thereof, according to claim 1, wherein R⁴ is methyl orCH₂CH₂OCH₃.
 6. A compound of formula (I), or a pharmaceuticallyacceptable salt thereof, according to claim 1, wherein R³ is

and R⁴ is H.
 7. A compound of formula (I), or a pharmaceuticallyacceptable salt thereof, according to claim 1, which is selected from:Example 1:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 2:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 3:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 4:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;6Example 5:-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 6:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-oneExample 7:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 8:6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 9:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 10:6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 11:(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 12:6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 13:(R)-6-(4-chlorophenyl)-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-(2-methoxypyridin-3-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 14:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 15:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 16:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 17:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 18:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(fluoromethyl)-8-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(2-methoxyethyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 19:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-14(R)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 20:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-((S)-3,3,3-trifluoro-2-hydroxypropyl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 21:6-(4-chlorophenyl)-3-cyclopropyl-5-(1,4-dimethyl-1H-benzo[d][1,2,3]triazol-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 22:6-(4-chlorophenyl)-3-cyclopropyl-5-(3-(difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 23:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 24:(R)-6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 25:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 26:6-(4-chlorophenyl)-3-cyclopropyl-5-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-1-(1-methyl-1H-pyrazol-5-yl)-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;Example 27: tert-butyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate; Example 28:5-(8-amino-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-4(1H)-one;and Example 29: ethyl(6-(6-(4-chlorophenyl)-3-cyclopropyl-1-methyl-4-oxopyrrolo[3,4-c]pyrazol-5(1H,4H,6H)-yl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)carbamate.8. A pharmaceutical composition comprising a therapeutically effectiveamount of a compound according to claim 1 or a pharmaceuticallyacceptable salt thereof and one or more pharmaceutically acceptablecarriers.
 9. A combination comprising a therapeutically effective amountof a compound according to claim 1 or a pharmaceutically acceptable saltthereof and one or more therapeutically active agents.
 10. A method ofmodulating BET protein activity in a subject, wherein the methodcomprises administering to the subject a therapeutically effectiveamount of the compound according to claim 1 or a pharmaceuticallyacceptable salt thereof.
 11. A method of claim 10, wherein said subjecthaving a cancer. 12.-14. (canceled)